Year	US Dollars
1961	0.25681
1962	0.74898
1963	1.37746
1964	1.659
1965	1.77211
1966	3.15846
1967	5.74577
1968	7.88975
1969	3.631
1970	6.44389
1971	7.30712
1972	15.81462
1973	19.98837
1974	34.74777
1975	74.13228
1976	62.73081
1977	107.81857
1978	96.30343
1979	159.64377
1980	127.40669
1981	129.85137
1982	128.11217
1983	137.95045
1984	97.61421
1985	105.87507
1986	132.72022
1987	198.8931
1988	168.76478
1989	162.07426
1990	213.51361
1991	251.68789
1992	269.08285
1993	283.26
1994	255.62225
1995	219.66586
1996	183.68767
1997	157.44107
1998	182.16593
1999	135.3376
2000	156.78666
2001	219.96443
2002	203.82576
2003	177.4968
2004	161.53302
2005	229.18367
2006	254.7801
2007	205.27304
2008	211.2239
2009	350.61293
2010	639.22907
2011	452.25134
2012	592.00299
2013	565.2224
2014	465.85743
2015	460.37992
2016	431.24586
2017	656.0709
2018	610.86979
2019	583.84654
2020	775.18623
2021	380.3185