Year	Percent
1991	89.062
1992	88.519
1993	88.96
1994	88.335
1995	88.294
1996	88.422
1997	87.387
1998	86.566
1999	85.825
2000	85.012
2001	84.662
2002	84.453
2003	84.327
2004	84.038
2005	83.596
2006	83.482
2007	83.06
2008	82.997
2009	82.864
2010	82.488
2011	82.042
2012	81.542
2013	80.987
2014	80.532
2015	80.313
2016	80.013
2017	79.999
2018	79.955
2019	79.9
2020	79.836
2021	79.774
2022	79.683