Year	US Dollars
1960	1.61674
1961	14.70053
1966	14.60719
1967	5.16557
1968	2.80978
1975	9.76324
1976	132.26912
1977	33.66593
1978	42.95319
1979	31.04708
1980	39.29637
1981	60.50217
1982	97.49235
1983	112.81052
1984	106.89302
1985	114.53282
1986	113.33811
1987	154.28724
1988	213.33823
1989	378.90076
1990	449.71456
1991	414.43241
1992	449.11181
1993	362.68744
1994	382.1193
1995	631.88978
1996	350.04284
1997	242.77909
1998	200.72966
1999	194.06522
2000	243.12175
2001	261.04555
2002	174.1179
2003	246.15964
2004	213.57413
2005	202.25137
2006	139.14617
2007	300.68592
2008	271.77537
2009	171.00062
2010	275.56028
2011	394.96035
2012	266.94889
2013	277.40933
2014	209.52218
2015	243.63079
2016	229.87607
2017	193.42807
2018	246.89606
2019	236.86039
2020	420.68964
2021	312.89918