Year	Percent
1990	1.303
1991	2.822
1992	5.738
1993	9.331
1994	9.336
1995	8.9411
1996	9.184
1997	9.6365
1998	9.2944
1999	7.4331
2000	5.1201
2001	3.9293
2002	4.2776
2003	4.8579
2004	5.5912
2005	6.0462
2006	5.1571
2007	4.1143
2008	4.0038
2009	6.4073
2010	6.3116
2011	5.6558
2012	6.0899
2013	6.0321
2014	6.0448
2015	5.8008
2016	5.6339
2017	5.5202