Year	Percent
1991	86.388
1992	85.89
1993	85.964
1994	86.352
1995	85.551
1996	85.251
1997	86.448
1998	87.491
1999	87.729
2000	89.141
2001	87.691
2002	87.594
2003	87.642
2004	88.171
2005	86.623
2006	86.759
2007	86.997
2008	86.836
2009	81.969
2010	82.791
2011	83.774
2012	83.131
2013	82.167
2014	81.599
2015	81.268
2016	81.006
2017	81.618
2018	82.455
2019	83.189
2020	83.813
2021	84.378
2022	84.877