Year	US Dollars adjusted for inflation)
1950	2398
1951	2684
1952	2749
1953	2725
1954	2749
1955	2862
1956	3000
1957	2975
1958	2901
1959	2788
1960	3048
1961	3219
1962	3441
1963	3612
1964	3723
1965	3857
1966	4083
1967	4124
1968	4203
1969	4291
1970	4629
1971	4706
1972	4717
1973	4868
1974	5123
1975	5205
1976	5182
1977	5114
1978	4784
1979	4777
1980	4970
1981	5051
1982	4987
1983	4323
1984	4338
1985	4337
1986	4714
1987	5034
1988	4488
1989	3776
1990	3523
1991	3510
1992	3417
1993	3494
1994	3827
1995	4047
1996	4079
1997	4261
1998	4158
1999	4152
2000	4205
2001	4145
2002	4265
2003	4351