Year	US Dollars adjusted for inflation)
1970	1419
1971	1493
1972	1453
1973	1537
1974	1479
1975	1372
1976	1214
1977	1168
1978	1137
1979	1166
1980	1154
1981	1099
1982	931.4
1983	988.2
1984	958.9
1985	954.8
1986	986.2
1987	958.8
1988	927.7
1989	884.3
1990	973.7
1991	892
1992	694.6
1993	560.4
1994	546.2
1995	498.1
1996	488.3
1997	479.8
1998	466.2
1999	409.2
2000	359.1
2001	348.1
2002	338.1
2003	435.5
2004	419.8