Year	US Dollars
2000	4.48
2001	4.91
2002	5.25
2003	5.08
2004	5.67
2005	6.16
2006	7.1
2007	7.96
2009	9.03
2010	9.39
2011	9.63
2012	11.83
2013	12.08
2014	12.59
2015	13.13
2016	14.71