Year	US Dollars
1960	0.84776
1961	1.0352
1962	0.85519
1963	1.50426
1964	1.77136
1965	1.59175
1966	1.34261
1967	1.21121
1968	0.91058
1969	0.88621
1970	1.86541
1971	1.7871
1972	2.21495
1973	2.42502
1974	2.10402
1975	2.86667
1976	3.02233
1977	4.88714
1978	4.71966
1979	8.33149
1980	9.66447
1981	10.26438
1982	10.84166
1983	10.44224
1984	9.18117
1985	10.73853
1986	14.50918
1987	17.59939
1988	19.58576
1989	21.68599
1990	18.20811
1991	18.58001
1992	18.76763
1993	14.07697
1994	17.62626
1995	17.06435
1996	14.54268
1997	13.56335
1998	12.98257
1999	12.10405
2000	12.6729
2001	13.93729
2002	13.20455
2003	17.63352
2004	16.52287
2005	15.4928
2006	17.06363
2007	20.84964
2008	22.8655
2009	26.23271
2010	28.25131
2011	27.48144
2012	28.16174
2013	31.89483
2014	32.18326
2015	44.34718
2016	38.20728
2017	45.04953
2018	50.94835
2019	46.22146
2020	59.92955
2021	52.1868