Year	Percent
1992	3.75405
1993	3.77819
1994	3.96517
1995	3.54879
1996	3.21618
1997	3.08391
1998	2.73798
1999	3.33164
2000	4.94175
2001	6.00957
2002	6.96976
2003	7.00417
2004	6.83781
2005	6.33034
2006	4.75809
2007	3.11905
2008	1.65575
2009	1.93497
2010	2.55804
2011	2.67157
2012	2.89397
2013	3.10295
2014	2.74737
2015	2.19553
2016	1.67932
2017	1.25601