Year	US Dollars
1960	0.03972
1961	0.07128
1962	3.70721
1963	3.13827
1964	15.67975
1965	12.60185
1966	11.29317
1967	12.02391
1968	11.95582
1969	13.02566
1970	9.73271
1971	11.83475
1972	10.40261
1973	16.43742
1974	28.13035
1975	27.61334
1976	22.78432
1977	22.54772
1978	39.11121
1979	54.60354
1980	45.7777
1981	67.47403
1982	47.37041
1983	52.88993
1984	57.06423
1985	44.54733
1986	86.46102
1987	96.12817
1988	84.30991
1989	97.07816
1990	107.71362
1991	80.92554
1992	83.06212
1993	60.16189
1994	75.5008
1995	75.56633
1996	64.89342
1997	46.90142
1998	54.21137
1999	56.54654
2000	44.53186
2001	42.62214
2002	43.73659
2003	43.91967
2004	99.67013
2005	63.90982
2006	77.1846
2007	74.83049
2008	89.76976
2009	83.47582
2010	74.73192
2011	81.90508
2012	81.30242
2013	73.14738
2014	79.35974
2015	60.55928
2016	49.56968
2017	59.91505
2018	64.14484
2019	89.87749
2020	98.04443
2021	81.74219