Year	Percent
1991	83.492
1992	83.229
1993	83.028
1994	84.525
1995	84.845
1996	84.466
1997	84.715
1998	83.779
1999	85.209
2000	85.34
2001	85.509
2002	86.138
2003	85.95
2004	87.175
2005	87.982
2006	85.928
2007	85.068
2008	86.569
2009	86.909
2010	87.667
2011	86.257
2012	85.252
2013	84.874
2014	83.822
2015	83.74
2016	82.416
2017	82.422
2018	82.397
2019	82.371
2020	82.344
2021	82.316
2022	82.287