Year	US Dollars adjusted for inflation)
1970	2763
1971	2861
1972	3185
1973	3744
1974	4139
1975	4478
1976	4551
1977	4830
1978	5130
1979	5469
1980	5519
1981	5464
1982	5415
1983	5334
1984	5490
1985	5475
1986	5929
1987	6456
1988	6628
1989	7036
1990	7393
1991	7230
1992	7054
1993	7075
1994	7244
1995	7397
1996	7519
1997	7609
1998	7682
1999	8311
2000	8517
2001	9025
2002	9329
2003	8934
2004	9193