Year	Percent
1991	64.947
1992	65.001
1993	64.937
1994	64.832
1995	64.744
1996	64.826
1997	64.863
1998	64.344
1999	63.867
2000	63.491
2001	63.083
2002	62.816
2003	62.49
2004	62.172
2005	63.945
2006	65.586
2007	66.708
2008	69.204
2009	71.637
2010	75.551
2011	76.267
2012	76.675
2013	76.96
2014	77.21
2015	76.538
2016	76.328
2017	76.491
2018	76.644
2019	76.792
2020	77.001
2021	77.232
2022	77.468