A comparison of the statistical data presented for 1979-80 and the data for the 75 libraries that were members in 1969-70 reveals a 91 percent increase in expenditures for library materials over the decade, while the gross number of volumes added yearly decreased by 22.5 percent. Library staff size has risen slightly over the decade, while salaries have more than doubled. The median number of volumes has increased by 44 percent since 1969-70 and microform units increased by 216 percent. Operating expenses have more than doubled over the past ten years. These and other conclusions are supported by seven chapters of tabular data and include the ARL statistics questionnaire, footnotes to the statistics, and a listing of ARL statistical compilations. (RAA)