Year	Percent
1983	4.5795
1984	5.324
1985	6.7214
1986	8.3249
1987	8.4842
1988	8.6072
1989	10.7422
1990	8.9091
1991	9.2876
1992	10.6561
1993	11.9853
1994	14.1116
1995	13.7033
1996	14.855
1997	17.2528
1998	17.6958
1999	15.1582
2000	14.1617
2001	12.8235
2002	12.0529
2003	12.944
2004	12.6754
2005	12.9887
2006	12.9569
2007	11.2014
2008	8.9253
2009	8.0542
2010	7.1736
2011	6.3248
2012	5.5164
2013	5.2184
2014	4.656
2015	4.1203
2016	3.5915
2017	3.0811