Year	US Dollars adjusted for inflation)
1966	422.35364
1967	414.07677
1968	443.95014
1969	444.02695
1970	459.24661
1971	446.07014
1972	433.63131
1973	458.92576
1974	470.8611
1975	513.41569
1976	535.39727
1977	538.34895
1978	556.21193
1979	532.57419
1980	547.97576
1981	547.1298
1982	523.84989
1983	559.26781
1984	556.02493
1985	528.16139
1986	525.03177
1987	512.80816
1988	511.02851
1989	517.76531
1990	515.33048
1991	513.05128
1992	514.02291
1993	514.46645
1994	501.11162
1995	491.59402
1996	488.55624
1997	498.20364
1998	501.08353
1999	517.77671
2000	530.10241
2001	543.78622
2002	509.72254
2003	527.50557
2004	546.77603
2005	524.51395
2006	513.75551
2007	515.77311
2008	528.37279
2009	544.95979
2010	562.48378
2011	521.6127
2012	533.77804
2013	542.13309
2014	530.31885
2015	536.41413
2016	531.91941
2017	534.26948