Year	Percent
1983	3.3333
1984	4.497
1985	8.4018
1986	9.5512
1987	8.2191
1988	5.7798
1989	8.2893
1990	5.2433
1991	5.9186
1992	4.8438
1993	4.5783
1994	3.7055
1995	2.7115
1996	4.0232
1997	4.1667
1998	3.5854
1999	2.9493
2000	2.4856
2001	2.4407
2002	3.4522
2003	2.2842
2004	3.041
2005	2.1489
2006	2.4959
2007	1.9496
2008	2.3162
2009	3.3436
2010	3.0492
2011	2.3661
2012	2.7196
2013	2.2643
2014	2.3657
2015	1.7345
2016	1.1249
2017	1.6297