Year	Percent
1991	71.679
1992	72.346
1993	76.345
1994	76.426
1995	75.886
1996	77.031
1997	80.092
1998	82.13
1999	83.768
2000	84.645
2001	84.416
2002	83.84
2003	85.086
2004	85.962
2005	86.42
2006	87.132
2007	86.036
2008	84.729
2009	82.753
2010	84.108
2011	85.776
2012	85.677
2013	86.306
2014	86.18
2015	85.952
2016	86.037
2017	85.954
2018	86.132
2019	86.329
2020	86.493
2021	86.575
2022	86.733