Year	Percent
1991	82.45
1992	82.657
1993	82.186
1994	82.044
1995	81.424
1996	80.715
1997	80.33
1998	80.13
1999	79.715
2000	79.314
2001	78.729
2002	77.978
2003	77.415
2004	76.706
2005	75.584
2006	75.165
2007	74.301
2008	73.07
2009	71.442
2010	69.33
2011	68.419
2012	65.073
2013	63.273
2014	62.145
2015	61.121
2016	60.08
2017	59.479
2018	58.071
2019	56.716
2020	55.812
2021	54.924
2022	53.988