Year	Percent
1996	12.4
1997	11.51
1998	10.01
1999	8.96
2000	8.24
2001	7.76
2002	7.6
2003	6.64
2004	5.24
2005	4.01
2006	3.61
2007	3.72
2008	3.6
2009	3.87
2010	4.3
2011	4.77
2012	3.79
2013	2.44
2014	2.3
2015	2.82
2016	2.03
2017	1.63