Year	US Dollars
1960	30.03533
1961	24.80457
1962	20.88386
1963	16.3912
1964	11.25839
1965	4.64098
1966	1.14954
1967	1.13012
1968	3.78148
1969	3.90805
1970	2.25228
1971	1.72086
1972	3.52246
1973	5.90618
1974	5.19857
1975	0.67631
1976	2.88761
1977	2.48642
1978	1.9319
1979	1.21764
1980	4.09421
1981	1.50706
1982	32.9571
1983	1.53348
1984	1.30171
1985	1.41953
1986	2.82623
1987	1.567
1988	1.36763
1989	2.36801
1990	1.96838
1991	1.72502
1992	0.73794
1993	0.63147
1994	0.85106
1995	1.23387
1996	0.78215
1997	0.81186
1998	1.11424
1999	0.92922
2005	4.0836
2006	6.27954
2007	3.18344
2008	11.91323
2009	6.29541
2010	1.17221
2011	103.60154
2012	14.8419
2013	21.52469
2014	34.48477
2015	25.41409
2016	28.57122
2017	67.70968
2018	46.8462
2019	44.78399
2020	44.48641
2021	51.23323