Year	Percent
1982	6.46
1983	4.66
1984	5.48
1985	5.69
1986	5.82
1987	7.21
1988	8.3
1989	7.68
1992	5.54
1993	4.9
1994	4.1
1995	4.54
1996	4.47
1997	3.8
1998	3.21
1999	2.86
2000	2.97
2001	3.44
2002	2.94
2003	3.08
2004	2.78
2005	2.77
2006	2.84
2007	2.33
2008	2.5
2009	3.69
2010	2.99
2011	2.76
2012	3.3
2013	3.13
2014	3.25
2015	3.19
2016	3.32
2017	3.35