Year	Percent
1990	14.54224
1991	14.72178
1992	20.46585
1993	15.79468
1994	14.33752
1995	13.97741
1996	11.243
1997	13.26286
1998	13.69832
1999	14.32235
2000	6.84955
2001	7.847
2002	8.01221
2003	10.18267
2004	9.52355
2005	7.78123
2006	5.6847
2007	7.83185
2008	12.90153
2009	11.4363
2010	5.57445
2011	9.0032
2012	7.97425
2013	7.7121
2014	7.68476
2015	7.27635