Year	US Dollars adjusted for inflation)
1970	3015
1971	3049
1972	3082
1973	3122
1974	3182
1975	3237
1976	3278
1977	3347
1978	3567
1979	3403
1980	3540
1981	3326
1982	3548
1983	3707
1984	4052
1985	4360
1986	4466
1987	3660
1988	3823
1989	3977
1990	4203
1991	4318
1992	4529
1993	4456
1994	4483
1995	4692
1996	4796
1997	5011
1998	5410
1999	5566
2000	5896
2001	5962
2002	6100
2003	6141