Year	Percent
1993	10.548
1994	9.846
1995	8.704
1996	8.329
1997	7.2007
1998	12.7417
1999	16.9449
2000	16.4492
2001	16.1674
2002	14.984
2003	17.4522
2004	17.9174
2005	19.051
2006	18.6734
2007	10.9697
2008	9.9315
2009	16.6965
2010	18.4776
2011	17.9611
2012	18.9975
2013	19.449
2014	17.1015
2015	14.4337
2016	11.4031
2017	8.7488