Year	Percent
1992	7.24
1993	7.28
1994	7.31
1995	7.35
1996	7.39
1997	7.43
1998	7.47
1999	7.51
2000	7.55
2001	7.59
2002	7.63
2003	7.67
2004	7.71
2005	7.75
2006	7.74
2007	7.73
2008	7.72
2009	7.71
2010	7.7
2011	7.67
2012	7.65
2013	7.62
2014	7.6
2015	7.57