Book preservation statistics show the scale of one major preservation strategy: mass deacidification. In the Library of Congress figures below, results are reported in physical volumes and book equivalents, while funding is reported in thousands of dollars. The historical figures cover fiscal years 1996 through 2018; the later cost figures include estimates for fiscal years 2019 through 2031.
Contents
- What these preservation measures count
- The early mass-deacidification record
- Annual treatment from 2002 to 2010
- Annual treatment from 2011 to 2018
- Physical volumes and book equivalents
- Program obligations and cost outlook
What these preservation measures count
Mass deacidification is presented here as a preservation activity measured in two different ways. A physical volume is a treated physical item. A book equivalent is a separate reporting measure used in the Library of Congress budget material. The two measures should not be treated as interchangeable: the same fiscal year can show a much larger number of book equivalents than physical volumes.
The reported unit also changes in the early record. For fiscal year 2002, the Library of Congress reported 170,600 physical volumes and zero book equivalents for manuscripts. That combination is a reminder that the table is a program-accounting record, not a single universal count of every format. The figures identify what was reported for each measure and period.
The source label for all figures in this article is the Library of Congress FY2020 budget justification. The historical results are not presented as independently verified here. Fiscal years are retained because they are the measurement periods used by the source.
The early mass-deacidification record
The first two entries in the supplied historical series use collection counts. During fiscal years 1996–1997, mass deacidification treated 92,000 collections, according to the Library of Congress FY2020 budget justification. From fiscal years 1997–2001, the reported treatment total was 306,258 collections.
Beginning with fiscal year 2002, the reporting shifts to physical volumes, book equivalents, and total obligations. The 2002 entry recorded 170,600 physical volumes and zero book equivalents for manuscripts. Total obligations for that fiscal year were $2,748 thousand.
Fiscal year 2003 recorded 215,319 physical volumes and 696,000 book equivalents. Total obligations were $3,687 thousand. In fiscal year 2004, the program recorded 299,064 physical volumes and 1,219,500 book equivalents, with total obligations of $4,681 thousand.
The next two years continued to report both treatment measures. Fiscal year 2005 recorded 296,119 physical volumes, 1,012,500 book equivalents, and $5,445 thousand in total obligations. Fiscal year 2006 recorded 298,826 physical volumes, 1,069,500 book equivalents, and $6,614 thousand in total obligations.
These early annual figures establish the series’ basic pattern: the source reports a physical-volume count, a book-equivalent count, and a financial obligation figure, but the magnitude of each measure varies independently.
Annual treatment from 2002 to 2010
The 2007–2010 period contains four further fiscal-year observations. In fiscal year 2007, mass deacidification treated 292,648 physical volumes and 1,086,000 book equivalents. Total obligations were $5,551 thousand, according to the Library of Congress FY2020 budget justification.
Fiscal year 2008 recorded 345,937 physical volumes and 1,066,500 book equivalents. Total obligations were $4,329 thousand. This is the highest physical-volume figure in the annual 2002–2018 series supplied here, while its book-equivalent figure remained close to the surrounding years.
In fiscal year 2009, the reported treatment totals were 325,830 physical volumes and 736,500 book equivalents. Total obligations were $6,284 thousand. Fiscal year 2010 recorded 330,497 physical volumes and 1,365,000 book equivalents, with total obligations of $5,444 thousand.
The annual record for this period can be read without combining the measures. Physical-volume counts range across the individual entries, while book-equivalent counts also move separately. The source does not provide a conversion rule in the supplied figures, so no conversion or per-item calculation is added here.
| Fiscal year | Physical volumes | Book equivalents | Total obligations ($ thousand) |
|---|---|---|---|
| 2007 | 292,648 | 1,086,000 | 5,551 |
| 2008 | 345,937 | 1,066,500 | 4,329 |
| 2009 | 325,830 | 736,500 | 6,284 |
| 2010 | 330,497 | 1,365,000 | 5,444 |
Source: Library of Congress FY2020 budget justification. These are fiscal-year figures, and the obligation amounts are reported in thousands of dollars.
Annual treatment from 2011 to 2018
From fiscal years 2011 through 2014, the reported physical-volume counts moved lower than the 2008 peak. Fiscal year 2011 recorded 288,334 physical volumes and 1,013,400 book equivalents, with total obligations of $5,664 thousand. Fiscal year 2012 recorded 258,087 physical volumes, 846,900 book equivalents, and $6,681 thousand in total obligations.
Fiscal year 2013 recorded 214,825 physical volumes and 851,450 book equivalents. Total obligations were $6,098 thousand. In fiscal year 2014, the figures were 195,027 physical volumes, 903,461 book equivalents, and $7,451 thousand in total obligations.
The later entries in the series continued to report both treatment measures. Fiscal year 2015 recorded 183,191 physical volumes and 232,105 book equivalents. Total obligations were $1,025,686 thousand. Fiscal year 2016 recorded 158,615 physical volumes and 188,737 book equivalents, with total obligations of $998,669 thousand.
Fiscal year 2017 recorded 168,969 physical volumes and 192,660 book equivalents. Total obligations were $589,857 thousand. Fiscal year 2018 recorded 167,138 physical volumes and 193,977 book equivalents, with total obligations of $1,214,800 thousand.
The source presents these obligation figures as total obligations in thousands of dollars. Because the supplied data does not explain the sharp change in the reported obligation amounts after fiscal year 2014, the amounts are reproduced as reported rather than interpreted.
Physical volumes and book equivalents
For fiscal years 2002–2018 combined, the Library of Congress FY2020 budget justification reports 4,816,942 physical volumes treated through mass deacidification. Over the same fiscal-year period, it reports 15,695,723 book equivalents. The two combined totals are separate program measures.
The annual data also illustrates why preservation statistics need a clear unit label. Fiscal year 2002 lists 170,600 physical volumes but zero book equivalents for manuscripts, while fiscal year 2010 lists 330,497 physical volumes and 1,365,000 book equivalents. Neither line can be reduced to a single count without an additional definition or conversion supplied by the source.
The 2011–2014 entries show book-equivalent totals of 1,013,400, 846,900, 851,450, and 903,461, respectively. The 2015–2018 entries show 232,105, 188,737, 192,660, and 193,977 book equivalents, respectively. These values belong to their stated fiscal years and should not be read as calendar-year measurements.
For readers comparing preservation programs, the safest comparison is therefore like-for-like: physical volumes with physical volumes, book equivalents with book equivalents, and obligations with obligations. A physical-volume ranking does not automatically rank book equivalents, and neither measure automatically ranks spending.
Program obligations and cost outlook
The Library of Congress FY2020 budget justification reports actual obligations of $92,677 thousand for fiscal years 2002–2018. It separately reports estimated obligations of $71,500 thousand for fiscal years 2019–2031. The latter period is an estimate, not a completed historical result.
Together, the source reports a total actual-and-estimated 30-year mass-deacidification program cost of $164,177 thousand. That total combines the actual 2002–2018 obligations with the estimated 2019–2031 obligations as presented in the budget justification. It should not be described as entirely spent, because the 2019–2031 component is identified as estimated.
The annual obligation entries provide the period-level context. From fiscal years 2002 through 2014, the listed amounts are $2,748 thousand, $3,687 thousand, $4,681 thousand, $5,445 thousand, $6,614 thousand, $5,551 thousand, $4,329 thousand, $6,284 thousand, $5,444 thousand, $5,664 thousand, $6,681 thousand, $6,098 thousand, and $7,451 thousand, respectively. These amounts are reported in the source’s unit of thousands of dollars.
For fiscal years 2015 through 2018, the listed total obligations are $1,025,686 thousand, $998,669 thousand, $589,857 thousand, and $1,214,800 thousand, respectively. They are retained exactly as reported by the Library of Congress FY2020 budget justification. The figures alone do not establish why the later amounts differ from the earlier entries, so this article does not assign a cause.
Taken together, the preservation statistics describe a long-running program through three distinct lenses: collections in the early fiscal-year record, physical volumes and book equivalents in the detailed annual record, and actual or estimated obligations in the financial record. Keeping those lenses separate makes the historical scale easier to interpret without turning unlike measures into a single unsupported total.