Year	Percent
1982	7.6
1983	8.86
1984	7.62
1985	6.5
1986	4.99
1987	5.32
1988	7.92
1989	11.53
1990	11.77
1991	12.84
1992	13.89
1993	13.92
1994	12.63
1995	19.11
1996	15.33
1997	14.94
1998	12.85
1999	12.29
2000	11.09
2001	12.17
2002	13.05
2003	11.86
2004	12.8
2005	11.49
2006	8.75
2007	7.41
2008	7.5
2009	9.19
2010	9.29
2011	8.65
2012	8.46
2013	9.13
2014	7.86
2015	9.91
2016	11.15
2017	10.37
2018	9.69
2019	9.96
2020	11.32
