Year	US Dollars
1960	2.92008
1961	6.39453
1962	3.18937
1963	4.0342
1964	4.06845
1965	6.95079
1966	3.97706
1967	2.85835
1968	4.01516
1969	3.23315
1970	2.38613
1971	3.67534
1972	3.53352
1973	4.78532
1974	3.44133
1975	5.4419
1976	4.17622
1977	7.96925
1978	12.15083
1979	16.03621
1980	26.89254
1981	17.34016
1982	23.29593
1983	18.07142
1984	15.79538
1985	17.01597
1986	23.54722
1987	16.72043
1988	25.02826
1989	23.72112
1990	13.71438
1991	23.58749
1992	30.93292
1993	48.06447
1994	63.43754
1995	49.08943
1996	41.98401
1997	26.78984
1998	23.93946
1999	16.47544
2000	39.40606
2001	68.89508
2002	74.55283
2003	63.01175
2004	67.99343
2005	59.82052
2006	65.46554
2007	92.69488
2008	62.2802
2009	71.45388
2010	71.2011
2011	64.10546
2012	64.77784
2013	64.47654
2014	128.00308
2015	129.45993
2016	92.50975
2017	70.48719
2018	64.64086
2019	70.36934
2020	102.10142
2021	82.7443