Year	US Dollars adjusted for inflation)
1991	3947.107
1992	3861.95
1993	3776.5
1994	3828.939
1995	4005.716
1996	4044.313
1997	3930.11
1998	3950.159
1999	3941.885
2000	3893.501
2001	3752.37
2002	3914.991
2003	3710.089
2004	3755.84
2005	3774.61
2006	3811.076
2007	3867.13
2008	3938.439
2009	3780.964
2010	3826.546
2011	3903.832
2012	3991.991
2013	4084.474
2014	4142.196
2015	4246.089
2016	4345.865
2017	4489.939
2018	4639.38
2019	4791.795
2020	4944.182
2021	5098.431
2022	5255.71