Year	US Dollars adjusted for inflation)
1991	3393.843
1992	3369.401
1993	3366.173
1994	3396.228
1995	3404.952
1996	3387.981
1997	3339.583
1998	3337.015
1999	3334.149
2000	3270.157
2001	3338.617
2002	3401.974
2003	3472.523
2004	3495.867
2005	3655.918
2006	3883.05
2007	3854.533
2008	4040.909
2009	3991.917
2010	4118.867
2011	4152.192
2012	4138.939
2013	4220.081
2014	4362.492
2015	4416.206
2016	4473.2
2017	4618.021
2018	4773.092
2019	4937.961
2020	5133.742
2021	5321.398
2022	5495.855