Year	Percent
1992	1.51
1993	1.29
1994	1.26
1995	0.93
1996	0.92
1997	1.21
1998	0.94
1999	1.64
2000	1.05
2001	5.74
2002	5.14
2003	6.43
2004	5.36
2005	5.14
2006	2.82
2007	4.37
2008	4.13
2009	5.08
2010	4.61
2011	4.51
2012	4.71
2013	4.43
2014	4.25
2015	4.03
2016	3.68
2017	3.65