Year	US Dollars
1960	0.32733
1961	2.76737
1962	4.98277
1963	3.03721
1964	2.76568
1965	1.1476
1966	18.30508
1967	3.28752
1968	2.49894
1969	1.42177
1970	1.94737
1971	6.68944
1972	4.88587
1973	4.29821
1974	4.39026
1975	22.70726
1976	20.41121
1977	24.04606
1978	51.91476
1979	39.17019
1980	126.81412
1981	74.67745
1982	30.1393
1983	55.37
1984	28.0387
1985	44.69937
1986	77.17075
1987	74.85704
1988	120.05115
1989	124.25609
1990	69.56885
1991	116.39027
1992	129.42426
1993	107.9542
1994	109.00036
1995	203.28573
1996	100.40138
1997	87.27327
1998	90.68796
1999	109.38079
2000	64.2108
2001	77.61273
2002	73.66124
2003	57.19553
2004	88.10631
2005	235.78422
2006	108.42841
2007	103.92894
2008	157.11686
2009	83.3436
2010	244.15404
2011	133.07874
2012	146.38527
2013	54.15145
2014	54.08674
2015	55.07574
2016	49.99427
2017	98.38245
2018	268.35701
2019	140.88974
2020	604.85424
2021	214.68692