Year	Percent
1991	69.337
1992	68.863
1993	69.1
1994	69.601
1995	70.057
1996	70.218
1997	70.659
1998	71.007
1999	71.178
2000	71.333
2001	70.16
2002	68.853
2003	67.964
2004	68.179
2005	68.538
2006	68.979
2007	68.622
2008	67.423
2009	63.503
2010	62.585
2011	62.858
2012	63.646
2013	63.72
2014	64.251
2015	64.757
2016	65.172
2017	65.263
2018	65.214
2019	64.925
2020	64.69
2021	64.392
2022	64.094