Year	US Dollars adjusted for inflation)
1970	3742.80828
1971	3834.02315
1972	4061.22012
1973	4233.10294
1974	4661.10073
1975	5532.03936
1976	6440.57462
1977	7197.15433
1978	7917.59386
1979	8659.98648
1980	9173.78781
1981	9408.16482
1982	9418.87477
1983	9230.17563
1984	9315.21348
1985	9389.62825
1986	9592.80063
1987	9918.57833
1988	10665.2248
1989	11425.79521
1990	12026.4033
1991	12439.03238
1992	12888.88383
1993	13332.57544
1994	13954.88599
1995	14736.87762
1996	15193.46201
1997	15871.60846
1998	16577.03279
1999	17256.85159
2000	18306.66506
2001	18280.21353
2002	18685.65569
2003	19035.36115
2004	18991.7828
2005	19585.12427
2006	19870.7522
2007	20590.95219
2008	21142.02081
2009	20466.5636
2010	21087.79469
2011	21276.41025
2012	21657.96957
2013	22340.75372
2014	23676.03236
2015	25342.02229
2016	26064.17138
2017	27145.81054