Year	Percent
1992	5.556
1993	9.512
1994	7.233
1995	5.342
1996	5.9713
1997	3.9101
1998	7.4149
1999	1.5338
2000	1.6391
2001	1.4272
2002	2.1189
2003	2.9369
2004	2.5866
2005	3.456
2006	3.851
2007	3.926
2008	5.0847
2009	6.2805
2010	7.2087
2011	8.2824
2012	8.0026
2013	7.4527
2014	5.9632
2015	5.5382
2016	4.4831
2017	4.2592