Year	US Dollars adjusted for inflation)
1977	3314.94412
1978	3601.26605
1979	3682.79255
1980	3555.03189
1981	3725.78185
1982	3755.58572
1983	3890.14097
1984	4110.17462
1985	4380.62934
1986	4916.12879
1987	5025.61561
1988	5601.42781
1989	6004.20091
1990	6493.29774
1991	6438.97233
1992	6853.38875
1993	6816.40262
1994	6856.08908
1995	6886.77903
1996	6996.27874
1997	6863.16036
1998	7195.66034
1999	7296.61162
2000	7216.90519
2001	6910.88188
2002	6877.974
2003	7121.56016
2004	7577.64684
2005	7482.70781
2006	7866.94926
2007	7855.14082
2008	8204.54189
2009	8213.88819
2010	8007.69648
2011	8000.14375
2012	7968.6816
2013	8200.49141
2014	8147.52355
2015	8270.70777
2016	8369.26496
2017	8554.58635