Year	US Dollars adjusted for inflation)
1977	2945.8794
1978	3141.9374
1979	3336.86959
1980	3302.72845
1981	3295.38085
1982	3338.44202
1983	3355.40121
1984	3388.50548
1985	3538.39645
1986	3783.98217
1987	4159.92186
1988	4340.90834
1989	4559.93712
1990	4771.77604
1991	4829.31433
1992	4751.55843
1993	4606.02557
1994	4632.19845
1995	4690.7301
1996	4872.62188
1997	5100.51161
1998	5688.9441
1999	6073.98599
2000	6359.78271
2001	6216.99579
2002	6414.885
2003	7003.12553
2004	6938.73825
2005	7837.35209
2006	7501.84215
2007	7936.04141
2008	7984.84152
2009	7430.56389
2010	7365.66666
2011	7393.88831
2012	7280.33653
2013	7421.47854
2014	7932.66826
2015	8406.77483
2016	8676.3392
2017	8957.59246