Year	Percent
1983	4.2881
1984	5.2786
1985	6.4293
1986	6.2274
1987	6.6926
1988	6.4758
1989	5.819
1990	5.1246
1991	5.4585
1992	3.9369
1993	5.3599
1994	5.3797
1995	3.887
1996	3.3527
1997	3.9856
1998	3.125
1999	3.2165
2000	2.842
2001	1.761
2002	2.2731
2003	1.994
2004	2.0752
2005	1.856
2006	2.3311
2007	2.2083
2008	2.3435
2009	2.8805
2010	3.1721
2011	3.4142
2012	3.69
2013	4.0793
2014	3.5387
2015	3.0021
2016	3.1033
2017	2.9998