Year	US Dollars adjusted for inflation)
1991	4540.993
1992	4554.045
1993	4665.721
1994	4450.329
1995	4470.062
1996	4518.671
1997	4518.859
1998	4510.957
1999	4262.215
2000	4454.119
2001	4529.053
2002	4633.21
2003	4842.596
2004	5113.373
2005	5291.167
2006	5206.041
2007	5260.249
2008	5236.381
2009	4892.356
2010	4944.393
2011	5117.006
2012	5261.08
2013	5092.681
2014	5007.837
2015	4837.038
2016	4861.837
2017	5005.738
2018	5118.549
2019	5234.628
2020	5354.35
2021	5481.738
2022	5614.617