Year	Percent
1983	4.42
1984	4.42
1985	6.07
1986	6.8
1987	7.21
1988	7.34
1989	8
1990	7.46
1991	7.29
1992	8.51
1993	10.44
1994	11.96
1995	11.63
1996	13.27
1997	15.19
1998	15.38
1999	14.19
2000	12.74
2001	11.99
2002	11.18
2003	12.61
2004	12.83
2005	12.74
2006	12.36
2007	10.34
2008	8.47
2009	7.99
2010	7.6
2011	6.42
2012	5.86
2013	5.69
2014	5.11
2015	4.7
2016	3.88
2017	3.39
2018	2.91
2019	2.7
2020	3.17