Year	Percent
1990	1.33
1992	1.06
1994	0.65
1996	1.98
1997	1.51
1998	1.64
1999	1.67
2000	1.6
2001	1.27
2002	1.42
2003	1.35
2004	1.55
2005	1.38
2006	1.32
2007	0.95
2008	1.04
2009	1.15
2010	2.45
2011	2.63
2012	2.46
2013	2.69
2014	2.63
2015	2.44
2016	2.59
2017	2.42