Year	US Dollars adjusted for inflation)
1991	6455.049
1992	6794.883
1993	7205.449
1994	7221.696
1995	7640.325
1996	7839.06
1997	8116.953
1998	7995.451
1999	8173.557
2000	8354.98
2001	8476.271
2002	8545.021
2003	8490.942
2004	8720.417
2005	8976.513
2006	9062.754
2007	9194.478
2008	9156.329
2009	8907.622
2010	8711.787
2011	8688.713
2012	8641.607
2013	8603.459
2014	8703.276
2015	8833.33
2016	9016.2
2017	9129.06
2018	9230.587
2019	9325.438
2020	9415.744
2021	9507.199
2022	9603.017