Year	Percent
1985	3.37
1987	5.99
1988	5.49
1989	4.96
1990	5.14
1991	5.76
1992	5.54
1993	6.08
1994	5.62
1995	5.53
1996	5.07
1997	5.45
1998	6.78
1999	6.61
2000	7.64
2001	2.5499
2002	7.98
2003	2.4106
2004	2.3553
2005	2.6288
2006	2.8305
2007	2.3165
2008	2.4944
2009	2.6449
2010	2.4596
2011	2.4513
2012	2.3561
2013	2.3098
2014	2.5351
2016	1.8278
2017	1.7357