Year	US Dollars
1960	1.14883
1961	2.21941
1962	3.05594
1963	4.22742
1964	8.15966
1965	8.29278
1966	7.56664
1967	6.99294
1968	10.6576
1969	6.0937
1970	7.95003
1971	6.64631
1972	7.43324
1973	5.92646
1974	8.06163
1975	11.90691
1976	11.33826
1977	14.06166
1978	16.90708
1979	23.45608
1980	22.5262
1981	20.95741
1982	17.72168
1983	16.36226
1984	24.70636
1985	14.7487
1986	24.58843
1987	33.24979
1988	42.90227
1989	45.48281
1990	52.45048
1991	55.89842
1992	57.14444
1993	48.48676
1994	46.50112
1995	43.02857
1996	47.77059
1997	32.73191
1998	40.50145
1999	40.71276
2000	39.90868
2001	35.7515
2002	32.22369
2003	42.98242
2004	40.88357
2005	44.97224
2006	55.10391
2007	56.80946
2008	66.57872
2009	54.10964
2010	69.08689
2011	52.70534
2012	75.14865
2013	70.67494
2014	56.5094
2015	61.97554
2016	71.33384
2017	85.01794
2018	69.64875
2019	61.88791
2020	75.02995
2021	58.05053