Year	Percent
1991	64.62
1992	63.61
1993	61.932
1994	61.275
1995	60.502
1996	59.902
1997	60.312
1998	61.323
1999	62.744
2000	65.564
2001	68.394
2002	69.324
2003	69.068
2004	68.068
2005	68.191
2006	66.601
2007	66.953
2008	66.997
2009	67.54
2010	67.588
2011	66.334
2012	64.899
2013	64.087
2014	64.755
2015	64.496
2016	64.423
2017	64.819
2018	64.793
2019	64.761
2020	64.724
2021	64.682
2022	64.638