Year	Percent
1990	8.502
1991	7.128
1992	7.773
1993	9.353
1994	8.092
1995	7.326
1996	5.968
1997	7.801
1998	6.807
1999	7.587
2000	6.269
2001	7.473
2002	9.455
2003	10.102
2004	10.99
2005	11.183
2006	9.0994
2007	9.148
2008	9.9817
2009	12.6093
2010	11.3886
2011	10.0719
2012	9.3776
2013	10.5527
2014	11.8345
2015	12.5913
2016	13.6322
2017	13.8933