Year	Percent
1991	85.007
1992	85.295
1993	85.366
1994	85.166
1995	84.511
1996	83.007
1997	81.343
1998	78.672
1999	81.56
2000	81.261
2001	78.943
2002	79.362
2003	77.919
2004	74.402
2005	71.386
2006	70.37
2007	69.483
2008	68.454
2009	68.056
2010	67.046
2011	65.945
2012	65.168
2013	65.132
2014	64.31
2015	60.641
2016	58.751
2017	58.73
2018	58.632
2019	58.538
2020	58.45
2021	58.363
2022	58.279