Year	Percent
1991	76.838
1992	76.883
1993	76.105
1994	78.783
1995	78.86
1996	77.673
1997	80.219
1998	79.521
1999	78.798
2000	78.659
2001	78.045
2002	78.55
2003	78.993
2004	79.419
2005	79.013
2006	79.629
2007	78.652
2008	80.365
2009	79.89
2010	80.287
2011	80.563
2012	78.813
2013	78.35
2014	80.686
2015	77.701
2016	77.99
2017	77.88
2018	77.83
2019	77.793
2020	77.771
2021	77.785
2022	77.815