Year	Percent
1991	63.649
1992	63.964
1993	64.353
1994	64.509
1995	64.399
1996	64.166
1997	63.521
1998	63.394
1999	71.388
2000	71.522
2001	69.446
2002	70.158
2003	71.633
2004	72.493
2005	72.404
2006	73.236
2007	72.456
2008	70.539
2009	68.492
2010	66.949
2011	65.916
2012	65.303
2013	65.113
2014	64.697
2015	64.972
2016	50.909
2017	50.922
2018	50.932
2019	50.943
2020	50.952
2021	50.961
2022	50.97