Year	US Dollars
1960	0.94
1961	1.25307
1962	1.68974
1963	1.127
1964	0.67798
1965	0.42379
1966	0.82492
1967	2.18274
1968	2.9873
1969	2.93011
1970	4.02991
1971	4.93886
1972	4.07361
1973	4.78963
1974	5.07975
1975	5.09834
1976	4.78275
1977	3.62646
1978	4.43133
1979	4.95145
1980	6.32291
1981	6.35812
1982	5.76408
1983	4.62666
1984	4.08712
1985	3.56387
1986	4.13976
1987	7.00128
1988	8.88342
1989	9.88191
1990	8.7426
1991	9.66551
1992	10.1795
1993	9.78469
1994	7.7218
1995	6.3175
1996	5.25376
1997	3.89771
1998	6.08928
1999	10.10659
2000	7.68632
2001	6.71624
2002	5.88787
2003	7.79375
2004	0.4318
2005	10.87825
2006	5.30623
2007	3.13823
2008	4.81502
2009	3.74589
2010	5.42489
2011	1.44925
2012	0.27579
2013	0.27429
2014	-1.49062
2015	-0.10985
2016	-0.41352
2017	1.05932
2018	3.60468
2019	-2.57201
2020	4.45023
2021	2.23698