Year	Percent
1992	5.557
1993	4.741
1994	5.667
1995	6.202
1996	6.123
1997	7.2
1998	8.16
1999	9.742
2000	7.095
2001	5.903
2002	4.845
2003	4.838
2004	4.467
2005	3.465
2006	3.425
2007	2.646
2008	3.425
2009	4.759
2010	4.0872
2011	3.6958
2012	2.5073
2013	3.0424
2014	2.7326
2015	3.0407
2016	2.9247
2017	3.2095