Year	US Dollars
1960	2.68763
1961	2.43647
1962	25.2984
1963	10.03659
1964	7.55689
1965	9.29618
1966	8.52064
1967	5.72143
1968	12.27324
1969	16.92614
1970	13.19096
1971	19.77695
1972	15.44027
1973	26.14653
1974	26.22304
1975	33.62255
1976	39.48129
1977	38.34544
1978	42.89362
1979	48.83447
1980	55.64847
1981	60.79046
1982	51.7455
1983	45.5887
1984	42.96605
1985	43.10884
1986	56.09581
1987	47.02045
1988	68.40928
1989	52.45217
1990	63.0678
1991	57.09502
1992	79.73474
1993	75.82381
1994	49.45606
1995	54.02362
1996	58.74171
1997	55.32134
1998	45.32236
1999	42.74843
2000	35.2789
2001	31.11777
2002	40.20515
2003	59.71064
2004	75.60915
2005	75.52665
2006	63.18772
2007	57.12695
2008	50.27149
2009	73.67568
2010	83.78545
2011	82.99618
2012	115.65662
2013	99.86283
2014	102.93154
2015	111.73136
2016	127.85682
2017	158.75623
2018	131.63278
2019	140.11421
2020	210.40349
2021	654.74092