Year	US Dollars
1960	3.31353
1961	1.67648
1962	1.1073
1963	1.66976
1964	2.13359
1965	3.03209
1966	3.76554
1967	1.43307
1968	3.02663
1969	0.81068
1970	0.68906
1971	0.76271
1972	5.27815
1973	2.98005
1974	16.15015
1975	21.76915
1976	18.65419
1977	20.82263
1978	24.69194
1979	43.4595
1980	40.31167
1981	36.28234
1982	41.36385
1983	51.11243
1984	32.07582
1985	57.62662
1986	47.0015
1987	44.01713
1988	45.49126
1989	35.80918
1990	40.21832
1991	40.41772
1992	24.6239
1993	20.20913
1994	17.98347
1995	10.19424
1996	9.13996
1997	5.6816
1998	8.43856
1999	9.60983
2000	8.56656
2001	7.13468
2002	11.06008
2003	22.00257
2004	34.49624
2005	61.817
2006	67.5318
2007	67.98689
2008	80.03776
2009	71.39914
2010	60.04309
2011	50.62229
2012	38.94022
2013	41.88109
2014	23.63793
2015	25.40398
2016	20.54719
2017	21.19994
2018	23.03766
2019	35.51621
2020	52.83921
2021	82.46673