Year	Percent
1995	21.7
1996	25.7
1997	25
1998	25.3
1999	23.2
2000	21.2
2001	23.4
2002	22.59
2003	24.6
2004	21
2005	22
2006	24.2
2007	19.2
2009	20.34
2010	21.45
2011	19.09
2012	20.45
2013	23.83
2016	22.2