Year	US Dollars adjusted for inflation)
1970	229.7
1971	235.5
1972	237.7
1973	252.9
1974	255.9
1975	266.6
1976	274.6
1977	288.2
1978	277.4
1979	334.3
1980	403.9
1981	410.7
1982	417.3
1983	448.9
1984	477.4
1985	457.6
1986	498.1
1987	588.6
1988	558.1
1989	589.4
1990	586.2
1991	598
1992	592.6
1993	598.5
1994	616.4
1995	659.6
1996	686.6
1997	787.4
1998	789.3
1999	813.6
2000	828.2
2001	830.8
2002	846.5
2003	933.5