Year	Percent
1991	64.361
1992	64.154
1993	63.862
1994	63.483
1995	63.002
1996	62.872
1997	62.614
1998	62.268
1999	61.908
2000	61.592
2001	61.277
2002	62.613
2003	62.457
2004	62.291
2005	62.069
2006	61.97
2007	62.552
2008	63.026
2009	64.002
2010	63.43
2011	62.69
2012	65.791
2013	68.907
2014	72.478
2015	72.264
2016	71.93
2017	72.111
2018	72.297
2019	72.485
2020	72.673
2021	72.867
2022	73.061