Year	US Dollars adjusted for inflation)
1955	2661
1956	2570
1957	2665
1958	2746
1959	2878
1960	3269
1961	3200
1962	3393
1963	3472
1964	3586
1965	4013
1966	4173
1967	4359
1968	4739
1969	5043
1970	5797
1971	6547
1972	7149
1973	7797
1974	7395
1975	7067
1976	8271
1977	7005
1978	6609
1979	6322
1980	5433
1981	4554
1982	4780
1983	4985
1984	5219
1985	5206
1986	4583
1987	4281
1988	4074
1989	3986
1990	4420
1991	4620
1992	5059
1993	5142
1994	5505
1995	5258
1996	5373
1997	5416
1998	5694
1999	5816
2000	6046
2001	6015
2002	6358
2003	6398