Year	Percent
1983	5.48
1984	6.53
1985	7.3
1986	7.68
1987	8.49
1988	8.22
1989	8.13
1990	7.83
1991	7.76
1992	8.8
1993	9.75
1994	11.07
1995	10.44
1996	10.95
1997	11.13
1998	10.83
1999	10.62
2000	9.27
2001	7.74
2002	7.76
2003	7.57
2004	7.95
2005	7.45
2006	7.22
2007	6.65
2008	6.03
2009	7.34
2010	7.58
2011	7.7
2012	8.25
2013	8.75
2014	9.18
2015	9.23
2016	8.91
2017	8.49
2018	8.08
2019	7.45
2020	7.06