Year	Percent
1983	5.68
1984	6.06
1985	6.25
1986	6.31
1987	6.65
1988	6.11
1989	5.5
1990	4.66
1991	5.05
1992	6.16
1993	7.38
1994	8.31
1995	7.65
1996	8.08
1997	8.93
1998	8.93
1999	8.03
2000	7.12
2001	7.2
2002	8.05
2003	9.26
2004	10.2
2005	10.4
2006	9.5
2007	7.98
2008	7
2009	7.29
2010	6.54
2011	5.4
2012	5
2013	4.87
2014	4.69
2015	4.38
2016	3.9
2017	3.53
2018	3.23
2019	2.99
2020	3.63