Year	Percent
1994	21.79
1995	21.44
1996	20.16
1997	21.05
1998	20.46
1999	19.15
2000	21.54
2001	21.35
2002	28.37
2003	28.51
2004	27.6
2005	27.79
2006	28.45
2007	40.8
2008	37.56
2009	36.01
2010	37.32
2011	35.75
2012	36.6
2013	38.77
2014	39.41
2015	39.92
2017	42.44