Year	US Dollars
1960	0.04181
1961	0.27819
1962	0.89958
1963	0.82822
1964	3.03382
1965	3.34824
1966	3.21584
1967	3.68063
1968	4.20684
1969	4.35118
1970	3.91862
1971	5.04398
1972	5.91186
1973	9.63143
1974	16.00494
1975	14.41733
1976	12.73891
1977	16.99818
1978	23.85
1979	29.061
1980	30.28429
1981	30.15695
1982	28.70736
1983	24.05199
1984	23.60583
1985	23.62271
1986	32.76263
1987	31.79373
1988	33.10125
1989	29.82271
1990	35.75918
1991	44.81016
1992	45.15055
1993	47.66122
1994	42.91834
1995	47.37154
1996	39.47196
1997	33.87153
1998	35.72161
1999	34.57391
2000	15.12932
2001	31.91408
2002	34.8528
2003	41.50541
2004	48.14674
2005	50.31591
2006	62.90408
2007	63.88258
2008	65.8235
2009	69.24591
2010	64.81541
2011	59.14597
2012	67.33306
2013	59.25696
2014	61.82552
2015	53.33844
2016	53.40874
2017	44.97663
2018	58.2345
2019	52.87367
2020	80.41909
2021	71.8376