Year	US Dollars adjusted for inflation)
1970	11830
1971	11680
1972	11540
1973	10780
1974	17750
1975	18690
1976	19710
1977	21460
1978	19650
1979	19000
1980	18490
1981	17410
1982	17760
1983	17620
1984	17160
1985	15660
1986	15590
1987	15570
1988	16440
1989	16660
1990	17190
1991	16360
1992	17100
1993	19600
1994	15800
1995	16910
1996	16870
1997	16890
1998	17050
1999	18050
2000	18650
2001	19090
2002	18880
2003	19560