Year	Percent
1992	1.8
1993	5.3
1994	6.6
1995	6.7
1996	9.3
1997	10.8
1998	9.4
1999	11.2
2007	9.81
2008	22.97
2009	18.44
2010	19.01
2011	18.44
2012	17.3
2013	16.18
2014	17.5
2015	18.26
2016	17.62
2017	17.7
2018	18.97
2019	18.3