Year	Percent
1991	0.672
1992	0.997
1993	1.435
1994	1.537
1995	2.342
1996	0.121
1997	0.159
1998	2.036
1999	0.444
2000	0.052
2001	0.421
2002	0.7583
2003	0.4823
2004	0.6622
2005	0.9032
2006	0.5785
2007	0.5083
2008	0.5585
2009	0.6411
2010	0.6251
2011	0.4242
2012	0.5415
2013	0.6569
2014	0.6715
2015	0.4513
2016	0.3343
2017	0.564