Year	Percent
1991	64.252
1992	63.126
1993	61.888
1994	61.153
1995	60.374
1996	59.993
1997	60.479
1998	61.216
1999	62.328
2000	65.099
2001	67.671
2002	68.634
2003	68.334
2004	67.531
2005	67.51
2006	66.125
2007	66.147
2008	65.958
2009	66.627
2010	66.513
2011	65.162
2012	63.987
2013	63.374
2014	63.863
2015	63.602
2016	63.508
2017	63.905
2018	63.879
2019	63.846
2020	63.808
2021	63.766
2022	63.721