Year	Percent
1990	9.08
1991	8.96
1992	9.39
1993	8.72
1994	8.26
1995	8.51
1996	8.73
1997	8.51
1998	8.11
1999	8.05
2000	8.08
2001	7.91
2002	8.28
2003	8.05
2004	7.73
2005	8.02
2006	8.47
2007	9.43
2008	9.63
2009	9.09
2010	9.18
2011	9.12
2012	9.16
2013	9.43
2014	9.62
2015	10.43
2016	10.61
2017	10.73
2018	11.63
2019	12.17