Year	US Dollars
1991	6.77741
1992	0.73423
1993	0.93708
1994	3.24729
1995	3.72149
1996	7.60613
1997	8.10204
1998	13.96729
1999	11.2745
2000	12.41902
2001	10.06842
2002	12.73912
2003	19.4218
2004	18.14496
2005	14.8676
2006	11.67553
2007	16.87205
2008	21.40339
2009	18.3237
2010	12.98809
2011	12.14154
2012	7.85251
2013	5.32768
2014	5.3678
2015	4.65718
2016	3.52814
2017	3.29808
2018	4.37667
2019	2.8957
2020	3.93748
2021	2.92722