Year	US Dollars
1963	0.04162
1964	0.04041
1965	0.62743
1966	0.19013
1967	0.03685
1968	0.49982
1969	0.34567
1970	0.70259
1971	0.45331
1972	0.59537
1973	1.57671
1974	1.78969
1975	5.96135
1976	8.84326
1977	7.70484
1978	8.01908
1979	12.33638
1980	19.40967
1981	22.51301
1982	25.44092
1983	27.12523
1984	35.54071
1985	42.6188
1986	73.40464
1987	71.12481
1988	67.85736
1989	68.15396
1990	74.22436
1991	97.51458
1992	96.93302
1993	118.53974
1994	138.93258
1995	131.66874
1996	106.23374
1997	108.50941
1998	94.12305
1999	114.92321
2000	80.21021
2001	90.52872
2002	96.95533
2003	114.8076
2004	110.97076
2005	118.75059
2006	137.27237
2007	140.31402
2008	114.5654
2009	145.29626
2010	137.8282
2011	166.33232
2012	224.15741
2013	187.6829
2014	177.41394
2015	130.8804
2016	68.82193
2017	156.77385
2018	141.60945
2019	232.80722
2020	262.05622
2021	163.19265