Year	Percent
1992	2.88761
1993	3.0549
1994	3.14327
1995	2.5139
1996	2.48151
1997	2.09019
1998	1.44239
1999	0.94084
2000	0.64978
2001	0.50348
2002	0.54325
2003	0.72929
2004	0.62315
2005	0.62485
2006	0.71132
2007	0.87568
2008	0.89814
2009	1.83692
2010	2.96696
2011	3.46453
2012	3.56646
2013	3.54314
2014	3.0593
2015	2.43978
2016	2.00302
2017	1.61286