Year	Percent
1990	6.89
1991	7.07
1992	7.75
1993	7.92
1994	7.92
1995	7.7
1996	8.56
1997	11.11
1998	6.61
1999	8.16
2000	7.46
2001	8.27
2002	8.19
2003	9.23
2004	10.39
2005	9.99
2006	11.52
2007	10.97
2008	10.41
2009	9.16
2010	8.81
2011	9.73
2012	10.64
2013	10.71
2014	10.79
2015	11.73
2016	13.28
2017	13.26
2018	13.96
2019	14.53