Academic
A survey reported in 1981 of 85 North American academic map libraries that had medium or large research collections (usable responses: 49 or 58%) in conjunction with data from the 2nd and 3rd editions of Map Collections in the United States and Canada showed that the average size of map collections had grown from 83,650 sheets in 1968 to 113,816 in 1975 (an increase of 36.0%) to 157,696 in 1980 (a further increase of 38.6%). The average annual accession rate for 1968 was 4,654 sheets; for 1975 it was 5,565 (an increase of 19.6%); and for 1980 it was 5,734 (a further increase of 3.0%). (Source)
Ibid. . . . showed that 77% of the respondents reported depository membership in the United States Geological Survey in 1968, 94% in 1975, and 96% in 1980. 84% reported depository membership in the Defense Mapping Agency in 1968, 86% in 1975, and 88% in 1980. 13% reported depository membership in the National Ocean Survey in 1968, 27% in 1975, and 49% in 1980. (Source)
