Year	US Dollars
1998	4.73
1999	5.28
2000	6.21
2001	6.63
2002	6.93
2003	6.58
2004	6.61
2005	6.63
2006	7.32
2007	8.26
2008	9.9
2012	11.66
2013	12.42
2014	13.26
2015	14.15
2016	15.09