Year	US Dollars adjusted for inflation)
1988	5885.18812
1989	3376.71179
1990	4230.91224
1991	5742.11087
1992	5852.92774
1993	6091.98163
1994	6416.32652
1995	6703.23023
1996	6961.33174
1997	6754.39114
1998	6949.23389
1999	6824.18316
2000	6747.63318
2001	6749.15226
2002	6656.7417
2003	6539.65727
2004	6636.30315
2005	6606.292
2006	6592.54408
2007	7157.55078
2008	7859.9442
2009	8501.10852
2010	8858.28398
2011	8450.10747
2012	8107.44417
2013	7753.87965
2014	7447.36434
2015	7189.63371
2016	7143.9591
2017	7197.63042