Year	Percent
1990	14.42
1991	14.63
1992	14.34
1993	14.25
1994	15.77
1995	16.8
1996	16.4
1997	16
1998	15.58
1999	15.16
2000	12.58
2001	10.34
2002	7.86
2003	8.21
2004	8.57
2005	8.94
2006	9.35
2007	10.64
2008	9.35
2009	10.27
2010	11.45
2011	10.14
2012	10.79
2013	10.2
2014	9.6
2015	9.92
2016	12.24
2017	11.42
2018	10.25
2019	9.83