Year	US Dollars
1960	5.24586
1961	5.2081
1962	1.59849
1963	4.27088
1964	4.14666
1965	4.33473
1966	4.2214
1967	5.41602
1968	4.57885
1969	5.95723
1970	5.49654
1971	6.54686
1972	5.87744
1973	5.67135
1974	8.23237
1975	6.0781
1976	7.97089
1977	11.16241
1978	10.21417
1979	8.14159
1980	9.88011
1981	13.9285
1982	22.20085
1983	13.24449
1984	11.87065
1985	9.47533
1986	14.54335
1987	15.86767
1988	16.7957
1989	23.50373
1990	14.36738
1991	32.05857
1992	16.85273
1993	24.23053
1994	20.09432
1995	26.3493
1996	15.27701
1997	17.02264
1998	12.32672
1999	14.73131
2000	15.65044
2001	13.21874
2002	12.48271
2003	12.23555
2004	6.37886
2005	11.61611
2006	12.46505
2007	21.58441
2008	24.54497
2009	28.35036
2010	19.47782
2011	13.68598
2012	17.65394
2013	21.7645
2014	10.24838
2015	9.7411
2016	14.12884
2017	22.4612
2018	25.55201
2019	19.51753
2020	45.98489
2021	26.11057