Year	US Dollars
1960	2.72337
1961	7.85713
1962	5.87308
1963	6.39171
1964	6.26811
1965	7.65938
1966	5.65258
1967	3.59864
1968	5.71987
1969	5.05546
1970	4.99865
1971	5.61838
1972	5.83142
1973	7.44255
1974	8.82918
1975	9.14304
1976	10.96278
1977	11.02807
1978	16.27912
1979	22.30002
1980	24.38914
1981	26.6979
1982	27.83219
1983	21.92096
1984	21.77924
1985	21.93381
1986	21.97126
1987	26.6841
1988	38.47338
1989	47.33381
1990	51.00062
1991	38.31637
1992	35.89106
1993	36.06002
1994	25.9385
1995	27.27437
1996	21.59131
1997	15.81744
1998	14.2518
1999	10.38707
2000	16.6578
2001	14.8555
2002	11.84326
2003	15.48548
2004	18.85299
2005	21.10788
2006	25.50152
2007	34.94932
2008	34.79224
2009	44.15966
2010	39.29053
2011	58.1403
2012	60.68864
2013	73.82597
2014	58.0607
2015	52.58232
2016	45.69172
2017	50.67037
2018	49.86677
2019	62.25377
2020	76.7508
2021	59.29372