Year	US Dollars adjusted for inflation)
1970	3016
1971	3163
1972	3473
1973	3790
1974	4113
1975	5121
1976	6022
1977	6726
1978	7652
1979	8449
1980	8570
1981	8732
1982	8547
1983	8905
1984	9113
1985	9417
1986	10080
1987	10360
1988	10860
1989	11660
1990	11960
1991	12730
1992	13740
1993	14070
1994	14620
1995	15080
1996	15820
1997	16570
1998	17260
1999	18030
2000	18860
2001	18770
2002	19380
2003	18790
2004	18640