Year	Percent
1983	7.5337
1984	8.242
1985	8.4682
1986	8.2338
1987	7.9199
1988	7.9023
1989	7.472
1990	6.119
1991	6.5251
1992	8.2263
1993	9.3198
1994	10.3158
1995	9.6285
1996	9.5933
1997	10.5914
1998	10.439
1999	9.2353
2000	8.2714
2001	7.7796
2002	8.2141
2003	9.2819
2004	10.0773
2005	10.8881
2006	10.1736
2007	8.7947
2008	7.6483
2009	7.3109
2010	6.4973
2011	5.5816
2012	5.1774
2013	4.9156
2014	4.6308
2015	4.2209
2016	3.741
2017	3.3144