Year	Percent
1998	43.56409
1999	43.55337
2001	41.41725
2002	42.73763
2003	40.78748
2004	38.24846
2005	55.35332
2006	34.35124
2007	37.44966
2008	32.91532
2009	30.72283
2010	34.32822
2011	33.90499
2012	36.45847