Year	Percent
1992	7.85
1993	8.9
1994	8.077
1995	7.661
1996	7.8773
1997	7.0347
1998	7.1821
1999	5.6742
2000	5.2885
2001	4.4665
2002	4.6473
2003	4.8866
2004	5.4062
2005	6.7856
2006	7.3563
2007	7.2942
2008	7.3848
2009	9.0429
2010	10.1253
2011	10.4444
2012	9.7082
2013	9.1518
2014	7.1519
2015	6.5561
2016	4.5401
2017	4.0164