Year	US Dollars adjusted for inflation)
1960	376.04518
1961	377.57275
1962	389.07074
1963	389.84348
1964	409.62213
1965	432.27229
1966	432.73473
1967	425.96198
1968	427.36301
1969	455.71725
1970	485.87342
1971	492.91463
1972	487.19359
1973	487.62668
1974	493.70595
1975	490.81315
1976	477.58876
1977	466.86109
1978	467.0023
1979	476.6463
1980	487.9631
1981	490.39023
1982	502.16142
1983	480.24734
1984	487.64569
1985	449.58246
1986	442.00708
1987	459.61092
1988	414.90349
1989	408.44315
1990	415.98064
1991	423.31091
1992	343.29473
1993	349.95526
1994	345.03702
1995	318.08852
1996	323.09802
1997	302.4773
1998	304.46864
1999	292.78277
2000	303.60688
2001	273.85091
2002	330.96578
2003	344.92729
2004	351.45321
2005	353.09169
2006	356.03128
2007	374.05777
2008	384.66146
2009	387.811
2010	399.15437
2011	414.54288
2012	466.58117
2013	550.54556
2014	562.85967
2015	437.16878
2016	453.66392
2017	462.4576