Year	US Dollars adjusted for inflation)
1980	2333.59793
1981	2154.99744
1982	2079.06121
1983	2090.16552
1984	2141.03709
1985	2146.68485
1986	2145.83322
1987	2174.26655
1988	2248.26345
1989	2189.62449
1990	2054.29485
1991	2011.52778
1992	1833.49114
1993	1348.48436
1994	1323.34467
1995	1476.23117
1996	1628.99484
1997	1700.39185
1998	1732.47197
1999	1720.82536
2000	1720.41165
2001	1735.52193
2002	1906.5292
2003	1924.28659
2004	2046.82618
2005	2387.82541
2006	2741.71228
2007	3259.23232
2008	3579.70277
2009	3537.61989
2010	3531.41688
2011	3539.54308
2012	3592.62377
2013	3705.25535
2014	3746.66049
2015	3729.00354
2016	3576.18689
2017	3484.59951