Year	US Dollars
1960	8.72451
1961	23.06428
1962	66.22644
1963	27.84746
1964	12.53986
1965	27.42919
1966	28.75071
1967	18.94724
1968	11.75283
1969	11.48064
1970	8.80727
1971	8.49062
1972	8.3777
1973	6.50156
1974	8.94063
1975	11.97034
1976	15.39731
1977	18.44927
1978	25.57581
1979	42.85639
1980	50.22853
1981	54.37531
1982	52.89602
1983	55.59109
1984	60.02684
1985	40.4023
1986	41.99734
1987	32.91957
1988	26.32357
1989	23.9791
1990	51.47233
1991	81.28459
1992	58.26682
1993	57.35731
1994	29.83252
1995	57.45833
1996	78.34513
1997	31.75849
1998	27.27696
1999	33.67694
2000	23.28663
2001	12.90561
2002	17.96707
2003	34.6107
2004	68.34063
2005	67.99399
2006	75.50797
2007	309.13856
2008	330.45649
2009	130.79164
2010	352.27002
2011	182.3063
2012	130.82734
2013	121.05085
2014	165.86059
2015	237.29009
2016	174.06781
2017	131.67367
2018	121.4773
2019	116.58702
2020	128.17872
2021	115.33642