Year	Percent
1983	9.1558
1984	7.7794
1985	6.373
1986	4.5564
1987	5.2023
1988	5.7833
1989	7.5095
1990	7.8352
1991	8.2972
1992	8.2906
1993	10.3958
1994	7.2075
1995	5.6135
1996	5.5365
1997	4.5162
1998	3.8497
1999	4.4853
2000	4.0398
2001	3.6238
2002	4.2355
2003	5.094
2004	4.999
2005	4.4358
2006	3.3325
2007	3.4485
2008	3.1672
2009	6.6258
2010	8.3577
2011	7.6689
2012	7.5079
2013	6.7459
2014	6.3822
2015	5.9229
2016	5.7684
2017	5.5691