Year	Percent
1986	8.05
1987	8.23
1988	11.08
1989	13.87
1990	14.49
1991	19.33
1992	19.15
1993	17.87
1994	15.46
1995	12.27
1996	12.25
1997	13.62
1998	15.01
1999	14.17
2000	13.51
2001	12.1
2002	11.73
2003	10.48
2004	9.66
2005	9.75
2006	9.94
2007	10.1
2008	11.41
2009	16.76
2010	17.41
2011	17.49
2012	17.99
2013	15.29
2014	14.1
2015	13.86
2016	13.45
2017	12.95
2018	11.8
2019	11.29
2020	12.41