Year	US Dollars adjusted for inflation)
1991	18073.027
1992	18987.043
1993	18766.883
1994	18673.641
1995	18486.254
1996	18646.516
1997	19035.545
1998	20074.158
1999	19271.803
2000	18425.859
2001	16640.277
2002	17712.525
2003	18403.797
2004	18895.031
2005	17726.568
2006	17746.766
2007	17019.457
2008	17027.221
2009	17126.836
2010	17638.588
2011	16945.947
2012	16446.701
2013	16838.922
2014	16734.367
2015	17105.273
2016	16399.625
2017	16241.864
2018	16295.981
2019	16601.25
2020	16988.498
2021	17531.945
2022	18115.613