Year	US Dollars
1997	5470
1998	5440
1999	5110
2000	5290
2001	5190
2002	5470
2003	6490
2004	8270
2005	9870
2006	10990
2007	12350
2008	13970
2009	13810
2010	13790
2011	14080
2012	13480
2013	13540
2014	13280
2015	12950
2016	12290
2017	12430