Year	US Dollars
1960	0.09808
1961	1.03157
1962	9.13174
1963	4.84771
1964	-5.72597
1965	1.45642
1966	2.86194
1967	2.46739
1968	1.72497
1969	1.06527
1970	0.43239
1971	0.68087
1972	0.69559
1973	0.67929
1974	0.40324
1975	0.28688
1976	-1.12412
1977	-0.59863
1978	-1.0485
1979	0.70866
1980	1.2807
1981	1.10433
1982	1.15545
1983	1.08119
1984	1.02812
1985	0.94872
1986	1.16904
1987	1.25214
1988	1.41696
1989	3.34833
1990	4.07482
1991	1.54206
1992	1.67774
1993	1.98799
1994	1.27259
1995	2.0292
1996	1.59843
1997	0.32121
1998	1.70993
1999	1.82668
2000	3.19882
2001	1.80947
2002	2.27351
2003	3.1968
2004	1.77947
2005	1.82985
2006	2.11238
2007	2.65285
2008	2.15008
2009	2.08452
2010	1.84955
2011	1.68373
2012	1.72342
2013	1.26785
2014	1.42846
2015	1.1985
2016	1.41275
2017	2.84163
2018	4.99838
2019	8.96945
2020	11.6425
2021	9.68515