Year	US Dollars
1996	20.88
1997	19.87
1998	19.63
2000	19.44
2001	17.78
2002	18.64
2003	19.04
2004	19.61
2005	20.18
2006	21.92
2007	22.99
2009	26.44
2010	26.16
2011	28.01
2012	30.36
2013	31.42
2014	31.86
2015	31.74
2016	32.14