Year	Percent
1991	83.537
1992	83.548
1993	82.984
1994	82.906
1995	83.987
1996	84.09
1997	84.854
1998	85.958
1999	86.602
2000	87.26
2001	87.824
2002	88.307
2003	88.441
2004	88.201
2005	88.778
2006	89.43
2007	89.409
2008	88.703
2009	89.667
2010	89.794
2011	90.221
2012	90.864
2013	90.843
2014	91.214
2015	91.329
2016	91.532
2017	91.57
2018	91.71
2019	91.891
2020	92.081
2021	92.243
2022	92.387