Year	Percent
1992	2.5261
1993	2.99897
1994	3.23275
1995	3.42828
1996	3.56355
1997	3.62996
1998	3.80762
1999	3.80177
2000	3.54305
2001	3.16054
2002	3.05632
2003	2.82947
2004	2.17464
2005	2.06264
2006	1.81507
2007	1.57367
2008	1.70555
2009	1.90432
2010	2.03607
2011	2.09515
2012	2.80753
2013	3.18642
2014	3.60917
2015	3.16976
2016	3.20496
2017	3.12133