Year	Percent
1986	5.26
1987	4.41
1992	3.68
1996	5.96
2001	9.158
2002	9.731
2003	8.21
2004	8.059
2005	6.693
2007	6.591
2008	6.819
2009	7.112
2010	6.5328
2011	5.7912
2012	5.6408
2013	5.5235
2014	5.0263
2015	4.932
2016	5.2257
2017	5.5215