Year	Percent
1990	5.919
1991	5.193
1992	5.271
1993	6.414
1994	6.048
1995	5.152
1996	3.985
1997	5
1998	4.805
1999	5.597
2000	4.59
2001	5.49
2002	7.536
2003	8.068
2004	8.482
2005	8.944
2006	7.1881
2007	7.3084
2008	8.1447
2009	10.9694
2010	9.9472
2011	8.7469
2012	8.2765
2013	9.361
2014	10.8759
2015	11.2932
2016	12.4572
2017	12.4128