Simple statistics for patent subsamples

United States corporationsUnited States universitiesUnited States government
Range of cited patents1963–19901965–19901963–1990
Range of citing patents1977–19931977–19931977–1993
Total potentially cited patents88,25710,76138,254
(1 in 10)(Universe)(Universe)
Total citations321,32648,806109,729
Mean citations3.64.52.9
Mean cited year197319791973
Mean citing year198619871986
Cited patents by field, %
 Drugs and medical4.8929.123.36
 Chemicals excluding drugs30.3728.7120.73
 Electronics, optics, and nuclear26.1627.3945.40
 Mechanical28.189.5117.09
 Other10.395.2813.42
Citations by region, %
 United States70.671.870.8
 Canada1.61.71.7
 European Economic Community14.513.216.8
 Japan11.311.08.6
 Rest of world1.92.42.1