Here is a table showing different estimates of the number of software patents granted in the U.S. for different years.
year LPF EDS EDS Ahoronian Classes
I II 364/395
1971 - - - 100 896
1972 - - 176 200 906
1973 - - - 150 871
1974 - - - 100 838
1975 - - 107 100 817
1976 - - - 100 1113
1977 - - - 100 1320
1978 - - 154 150 1272
1979 - - - 200 986
1980 - - - 250 1239
1981 - 21 157 300 1257
1982 - 52 - 300 1446
1983 - 64 - 350 1517
1984 - 136 413 400 1857
1985 - 153 - 500 1978
1986 - 187 - 600 2202
1987 - 227 820 800 2766
1988 - 183 - 800 2708
1989 - 579 - 1600 3980
1990 - - 1201 1300 3606
1991 - - - 1500 3817
1992 2000 - - 1624 4073
1993 - - 2007 2400 4862
1994 - - - 4500 -
This data is also available as a postscript
(13k), or jpeg (87k) graph (GIF unavailable due to patent complications).
2000 software patents granted in 1992 is a figure computed by the LPF. EDS has published two sets of figures that contain quite different values. We believe the first set of figures was produced using automated software that was not very good. Gregory Ahoronian has produced estimates that agree quite closely with the one estimate the LPF made. The final column is not an estimate of software patents per se, but the number of patents issued in classes 364 and 395, the main patent office classes in which software patents are issued. The majority of the growth in these classes can be attributed to software patents.