Year	US Dollars adjusted for inflation)
1970	30940
1971	31190
1972	32530
1973	34240
1974	35590
1975	34680
1976	40130
1977	43230
1978	44750
1979	52920
1980	47120
1981	36020
1982	35270
1983	34920
1984	34000
1985	32390
1986	30480
1987	30080
1988	29450
1989	28260
1990	28170
1991	28460
1992	27340
1993	26700
1994	26440
1995	26250
1996	26760
1997	26860
1998	26750
1999	24970
2000	25110
2001	25320
2002	25590
2003	26240