Year	Percent
1990	90.57
1991	90.1
1992	89.56
1993	88.94
1994	88.25
1995	87.49
1996	86.75
1997	85.93
1998	85.04
1999	84.32
2000	83.56
2001	82.87
2002	82.2
2003	81.56
2004	80.97
2005	80.44
2006	79.97
2007	79.57
2008	79.24
2009	78.97
2010	78.76
2011	78.59
2012	78.47
2013	78.36
2014	78.23
2015	78.59
2016	78.87
2017	79.07
2018	79.18
2019	79.22
2020	78.87