Year	Percent
1992	8.722
1993	10.39
1994	9.371
1995	8.687
1996	9.0314
1997	7.861
1998	8.0905
1999	6.2157
2000	5.7865
2001	4.8774
2002	5.0777
2003	5.3862
2004	5.8567
2005	7.4269
2006	7.912
2007	7.7335
2008	8.0042
2009	9.7408
2010	10.6633
2011	10.9836
2012	10.6107
2013	10.1355
2014	7.913
2015	7.0391
2016	5.108
2017	4.5708