Year	Percent
1995	55.31
1996	55.3
1997	56.31
1998	59.61
1999	56.82
2000	52.42
2001	47.12
2002	40.79
2003	43.66
2004	42.44
2005	39.4
2006	42.81
2007	44.26
2008	41.04
2009	42.69
2010	44.69