Year	US Dollars adjusted for inflation)
1991	3924.784
1992	3892.489
1993	4015.832
1994	3769.047
1995	4036.666
1996	4133.147
1997	3820.526
1998	3800.612
1999	3966.305
2000	3804.334
2001	3770.526
2002	3683.303
2003	3797.631
2004	3900.09
2005	4132.554
2006	4780.932
2007	4765.093
2008	4678.046
2009	4493.595
2010	4580.069
2011	4655.385
2012	4780.513
2013	4908.675
2014	5014.032
2015	4910.933
2016	4857.243
2017	4915.62
2018	5035.499
2019	5176.123
2020	5335.093
2021	5504.417
2022	5689.327