Year	Percent
1985	16.07
1987	20.37
1988	18.45
1989	21.98
1990	19.16
1991	21.61
1992	20.4
1993	20.75
1994	20.88
1995	19.14
1996	17.57
1997	18.52
1998	21.53
1999	25.3
2000	29.48
2001	12.8439
2002	30.33
2003	11.867
2004	11.8396
2005	11.8875
2006	12.4348
2007	10.911
2008	12.438
2009	12.8082
2010	11.9947
2011	11.9023
2012	11.6512
2013	11.2386
2014	11.3334
2016	9.2051
2017	8.9099