Year Total (trillion 1987 dollars) Per Person (1987 dollars)
1950 3.8 1,487
1955 4.9 1,763
1960 6.1 2,008
1965 7.9 2,362
1970 10.1 2,727
1975 11.9 2,912
1980 14.1 3,165
1985 16.0 3,297
1990 18.8 3,549
1994 (prel) 20.1 3,577
*Source: Brown, Lester R. Nicholas Lenssen, and Hal Kane. 1995. Vital Signs: The Trends That Are Shaping Our Future 1995-1996. The WorldWatch Institute. P. 71.