Year	Percent
1995	27.5
1996	28
1997	28.5
1998	27.5
1999	27.7
2000	33.98
2001	27.37
2002	29.47
2003	33.13
2004	32.65
2005	31.27
2006	32.29
2007	35.23
2008	27.3
2009	19.8
2010	19.48
2011	23.06
2012	24.57
2013	20.95
2014	18.83
2015	17
2016	12.84
2017	9.96