Year	US Dollars adjusted for inflation)
1981	2232.41243
1982	2239.36644
1983	2470.85177
1984	2449.22118
1985	2189.83178
1986	2600.35042
1987	2712.35207
1988	2796.88827
1989	2644.48774
1990	2630.06799
1991	2568.46389
1992	2701.54791
1993	2825.47128
1994	2960.37206
1995	3175.88412
1996	2827.28254
1997	2630.15494
1998	2543.88128
1999	2475.55846
2000	2617.36543
2001	2756.47586
2002	2829.93701
2003	2837.03618
2004	2842.69012
2005	2926.63527
2006	2967.37123
2007	3072.29376
2008	3017.07107
2009	2961.92709
2010	3146.76395
2011	3177.63858
2012	3279.9636
2013	3365.46542
2014	3333.36105
2015	3315.19294
2016	3373.94554
2017	3454.32339