Year	US Dollars adjusted for inflation)
1970	3898
1971	4150
1972	4530
1973	4991
1974	5339
1975	5821
1976	6299
1977	6639
1978	6762
1979	6582
1980	6236
1981	5653
1982	5118
1983	5318
1984	5539
1985	5839
1986	6057
1987	6161
1988	6338
1989	6292
1990	5897
1991	5793
1992	5906
1993	6133
1994	6384
1995	6792
1996	7180
1997	7631
1998	7969
1999	8305
2000	8611
2001	8728
2002	8867
2003	9217
2004	9708