Year	Percent
1992	3.4841
1993	2.77495
1994	2.44128
1995	2.57589
1996	2.91559
1997	2.61828
1998	2.94866
1999	2.64938
2000	3.36054
2001	3.17172
2002	2.87856
2003	3.07392
2004	3.33712
2005	3.78952
2006	3.74076
2007	3.03647
2008	4.31612
2009	6.10116
2010	6.68522
2011	5.87399
2012	6.95277
2013	7.81267
2014	8.69597
2015	8.7771
2016	8.45664