Year	Percent
1991	0.16575
1992	0.29675
1993	0.78165
1994	0.85238
1995	0.83609
1996	0.53764
1997	0.4998
1998	0.46779
1999	0.24558
2000	0.31704
2002	0.43101
2003	0.44698
2004	0.77244
2005	0.32847
2006	0.34461
2007	0.22962
2008	0.20539
2009	0.93919
2010	1.65245
2011	1.49109
2012	1.26463
2013	0.97101
2014	0.81451
2015	0.58013
2016	0.29088
2017	0.3146