Year	US Dollars
1960	104.12343
1961	102.92113
1962	87.44778
1963	84.45679
1964	73.38892
1965	63.05591
1966	65.58831
1967	42.26977
1968	33.46153
1969	33.09402
1970	51.41989
1971	39.3016
1972	64.10772
1973	116.20368
1974	170.39984
1975	260.61201
1976	294.68301
1977	219.90428
1978	228.18573
1979	683.45965
1980	710.96029
1981	541.47239
1982	375.67286
1983	339.65925
1984	266.68299
1985	220.76022
1986	219.77922
1987	214.44631
1988	150.66624
1989	102.22733
1990	273.41939
1991	256.19555
1992	109.97735
1993	76.26555
1994	87.37623
1995	121.23516
1996	110.46122
1997	100.4655
1998	85.44087
1999	87.90543
2000	109.60461
2001	87.21343
2002	106.66601
2003	244.84643
2004	109.28846
2005	125.00585
2006	94.4063
2007	97.55375
2008	110.67452
2009	109.19855
2010	137.74556
2011	137.0046
2012	160.49944
2013	181.9836
2014	311.52135
2015	225.51028
2016	273.76459
2017	291.68368
2018	241.50408
2019	251.41881
2020	284.94094
2021	308.9984