Year	US Dollars adjusted for inflation)
1991	17360.869
1992	17468.77
1993	16819.494
1994	16357.857
1995	17419.65
1996	16784.234
1997	15846.9
1998	16527.02
1999	17015.49
2000	17605.609
2001	17084.844
2002	17284.658
2003	17588.283
2004	16609.859
2005	16718.182
2006	16078.232
2007	16581.504
2008	16190.943
2009	15941.366
2010	16076.192
2011	16217.826
2012	16606.082
2013	16196.396
2014	17571.225
2015	18112.725
2016	18358.566
2017	18313.152
2018	18460.609
2019	18507.543
2020	18657.887
2021	18911.01
2022	19223.641