Year	US Dollars
1960	0.29493
1961	0.28266
1962	1.76926
1963	1.56788
1964	5.92475
1965	2.96882
1966	7.72696
1967	15.64355
1968	7.52015
1969	4.86895
1970	3.09225
1971	4.86145
1972	4.75729
1973	9.65124
1974	11.92306
1975	17.48036
1976	12.12874
1977	20.63519
1978	34.12686
1979	49.82658
1980	55.45205
1981	39.13535
1982	51.79764
1983	34.17384
1984	36.33283
1985	47.7518
1986	65.49298
1987	59.5291
1988	65.08896
1989	48.95295
1990	61.77273
1991	111.41092
1992	127.66126
1993	104.81546
1994	84.38893
1995	233.83677
1996	68.30585
1997	66.75568
1998	37.14618
1999	64.77441
2000	80.33961
2001	56.00883
2002	77.15144
2003	71.08802
2004	100.86217
2005	101.08631
2006	122.8135
2007	82.44509
2008	86.72706
2009	95.42061
2010	66.65562
2011	72.44381
2012	64.91436
2013	75.17242
2014	63.39707
2015	49.09335
2016	57.63799
2017	60.1507
2018	56.08466
2019	51.56776
2020	53.67579
2021	54.98655