Year	US Dollars adjusted for inflation)
1990	13988.6576
1991	12393.60008
1992	12318.22051
1993	12313.04032
1994	12666.68851
1995	13462.9868
1996	14047.84332
1997	13979.36297
1998	13946.61807
1999	14160.91238
2000	14806.58347
2001	15294.62929
2002	15577.3922
2003	16143.26364
2004	16930.1897
2005	18011.3867
2006	19193.75482
2007	20151.17812
2008	20520.77996
2009	19424.27306
2010	19808.07109
2011	20118.58781
2012	19929.76407
2013	19826.79194
2014	20343.68375
2015	21381.70308
2016	21894.11265
2017	22779.2919