Year	US Dollars
1960	0.42469
1961	5.38581
1962	6.4636
1963	8.07404
1964	5.37511
1965	8.04581
1966	11.3912
1967	26.00473
1968	23.05849
1969	24.5011
1970	37.95463
1971	43.39284
1972	70.63047
1973	98.5181
1974	92.03813
1975	93.28389
1976	65.99237
1977	103.01533
1978	171.3613
1979	151.56839
1980	313.41982
1981	247.27273
1982	239.77008
1983	256.07835
1984	177.23224
1985	177.19014
1986	193.50775
1987	249.90706
1988	221.67969
1989	230.54088
1990	256.64236
1991	249.56927
1992	327.21017
1993	192.55812
1994	177.66371
1995	178.32378
1996	155.61619
1997	186.57778
1998	203.01847
1999	240.35101
2000	190.59735
2001	122.27855
2002	217.74893
2003	172.10663
2004	151.31361
2005	271.38258
2006	254.98836
2007	269.71117
2008	259.50791
2009	237.2731
2010	220.10279
2011	587.41616
2012	588.34595
2013	573.55418
2014	701.48283
2015	556.52186
2016	513.3614
2017	640.98305
2018	654.58322
2019	456.04913
2020	458.79032
2021	564.81525