Year	US Dollars
1978	2.86171
1985	0.28512
1986	0.27686
1987	0.82396
1988	0.44758
1989	0.40547
1990	0.37164
1991	0.40823
1992	0.49394
1993	0.64575
1994	0.25605
1995	0.60217
1996	1.1307
1997	3.87386
1998	4.57182
1999	8.6591
2000	3.14759
2001	5.01392
2002	11.18518
2003	5.51432
2004	6.71638
2005	3.62848
2006	2.2768
2007	4.08802
2008	8.4282
2009	2.65321
2010	3.19325
2011	4.78095
2012	3.93245
2013	4.36368
2014	6.11037
2015	5.2035
2016	4.71256
2017	5.21705
2018	4.70042
2019	5.20511
2020	4.79715
2021	0.70076