Year	Percent
1992	1.57966
1993	2.07838
1994	2.58615
1995	2.50344
1996	2.82501
1997	3.3715
1998	3.38178
1999	3.0841
2000	2.74477
2001	2.71557
2002	2.99398
2003	3.72459
2004	4.01398
2005	4.39462
2006	4.08122
2007	3.35754
2008	2.79343
2009	2.78568
2010	2.60116
2011	2.11921
2012	1.88631
2013	1.86584
2014	1.7987
2015	1.68955
2016	1.45122
2017	1.39106