Year	Percent
1991	63.242
1992	64.667
1993	64.668
1994	64.687
1995	64.751
1996	64.637
1997	64.458
1998	65.442
1999	66.139
2000	66.626
2001	67.116
2002	67.374
2003	67.555
2004	67.324
2005	66.992
2006	66.578
2007	65.986
2008	65.235
2009	64.28
2010	63.099
2011	61.668
2012	59.959
2013	59.321
2014	57.745
2015	57.53
2016	57.447
2017	57.554
2018	57.669
2019	57.796
2020	57.932
2021	58.079
2022	58.383