Year	Percent
1990	1.225
1991	2.181
1992	3.716
1993	6.29
1994	6.765
1995	6.2647
1996	7.1751
1997	8.5323
1998	7.386
1999	5.901
2000	4.7618
2001	3.4273
2002	3.5281
2003	4.0257
2004	4.9864
2005	5.9085
2006	5.4677
2007	4.7288
2008	4.6561
2009	5.9598
2010	6.63
2011	5.8535
2012	5.7347
2013	6.1015
2014	5.9038
2015	5.7747
2016	5.3339
2017	5.2129