Year	Percent
1991	79.228
1992	78.42
1993	80.409
1994	80.978
1995	81.321
1996	82.21
1997	82.331
1998	82.704
1999	82.737
2000	83.198
2001	83.328
2002	83.976
2003	85.022
2004	84.947
2005	85.753
2006	86.159
2007	86.426
2008	87.317
2009	87.917
2010	88.175
2011	87.686
2012	88.003
2013	88.129
2014	88.764
2015	89.069
2016	89.208
2017	89.108
2018	89.245
2019	89.359
2020	89.477
2021	89.583
2022	89.669