Year	Percent
1991	87.908
1992	87.23
1993	86.116
1994	85.602
1995	85.401
1996	84.608
1997	84.305
1998	84.007
1999	83.126
2000	82.334
2001	80.627
2002	79.178
2003	78.393
2004	76.629
2005	74.796
2006	73.204
2007	71.032
2008	69.104
2009	67.666
2010	65.884
2011	64.973
2012	64.342
2013	63.559
2014	62.201
2015	61.443
2016	61.706
2017	61.686
2018	61.557
2019	61.427
2020	61.307
2021	61.198
2022	61.095