Year	Percent
1983	2.29
1984	1.94
1985	2.15
1986	1.84
1987	1.94
1988	1.46
1989	1.29
1990	1.37
1991	1.29
1992	1.79
1993	2.11
1994	2.99
1995	2.5
1996	2.7
1997	2.07
1998	2.51
1999	1.99
2000	2.01
2001	1.42
2002	2.36
2003	3.2
2004	4.44
2005	3.91
2006	4.1
2007	3.37
2008	4.17
2009	4.22
2010	3.91
2011	4.29
2012	4.47
2013	5.33
2014	4.87
2015	5.83
2016	5.33
2017	4.9
2018	5.04
2019	4.7
2020	5.7