Year	US Dollars
1960	0.42538
1961	0.41778
1962	0.77048
1963	2.41478
1964	2.64653
1965	5.90465
1966	7.75469
1967	5.51114
1968	7.3888
1969	8.25854
1970	6.669
1971	6.24007
1972	6.25243
1973	4.24397
1974	3.66167
1975	12.16571
1976	5.85593
1977	8.32941
1978	10.04906
1979	14.60791
1980	16.08142
1981	11.80058
1982	11.02346
1983	8.34788
1984	15.97303
1985	14.23513
1986	25.68624
1987	28.58123
1988	39.23137
1989	47.53579
1990	36.23491
1991	55.45691
1992	37.81782
1993	37.68769
1994	32.14158
1995	37.26559
1996	36.49796
1997	27.05107
1998	37.61106
1999	31.81398
2000	30.54334
2001	31.93026
2002	33.20933
2003	46.18202
2004	64.77592
2005	51.23539
2006	53.52059
2007	49.05114
2008	53.94086
2009	63.51229
2010	66.36319
2011	68.83439
2012	66.9908
2013	48.25218
2014	39.83245
2015	61.32395
2016	44.61787
2017	41.80859
2018	34.58399
2019	28.89987
2020	68.49573
2021	37.3837