Year	Percent
1982	0.63
1983	0.77
1984	2.34
1985	1.85
1986	1.22
1987	1.47
1988	2.21
1989	3.75
1990	4.32
1991	4.34
1992	4.8
1993	5
1994	4.46
1995	4.39
1996	3.44
1997	3.19
1998	2.27
1999	1.9
2000	2.39
2001	2.51
2002	2.86
2003	3.42
2004	3.26
2005	3.71
2006	2.92
2007	1.91
2008	1.92
2009	2.41
2010	2.96
2011	2.7
2012	2.58
2013	2.88
2014	3.29
2015	4
2016	4.29
2017	3.72
2018	3.41
2019	3.15
2020	3.85