Year	Percent
1982	2.91
1983	3.64
1984	3.48
1985	3.43
1986	2.89
1987	3.49
1988	3.29
1989	2.91
1990	2.99
1991	3.24
1992	3.31
1993	3.96
1994	3.29
1995	4.12
1996	5.11
1997	4.76
1998	5.04
1999	4.53
2000	4.27
2001	3.58
2002	4.44
2003	4.25
2004	4.83
2005	4.85
2006	4.6
2007	4.24
2008	3.61
2009	4.72
2010	4.38
2011	3.98
2012	4.33
2013	4.9
2014	5.19
2015	5.18
2016	5.42
2017	5.14
2018	4.41
2019	4.17
2020	4.96