Year	US Dollars adjusted for inflation)
1991	36376.77
1992	36585.516
1993	35143.73
1994	34012.453
1995	34878.973
1996	34371.863
1997	35156.352
1998	34277.125
1999	32696.523
2000	32407.002
2001	32331.615
2002	29989.959
2003	27245.443
2004	30015.842
2005	31138.029
2006	32379.826
2007	34036.047
2008	34783.172
2009	33369.836
2010	32500.385
2011	32983.102
2012	34329.781
2013	34107.789
2014	32127.83
2015	29909.529
2016	26911.268
2017	24265.285
2018	22404.617
2019	21963.119
2020	22594.139
2021	23416.924
2022	24131.426