Year	Percent
1991	77.148
1992	78.062
1993	77.959
1994	78.005
1995	77.889
1996	78.075
1997	78.111
1998	78.465
1999	78.916
2000	79.09
2001	79.51
2002	79.828
2003	79.705
2004	79.443
2005	79.928
2006	79.92
2007	79.847
2008	80.149
2009	79.915
2010	80.641
2011	80.364
2012	79.821
2013	79.428
2014	79.066
2015	79.045
2016	78.746
2017	78.662
2018	78.387
2019	78.013
2020	77.686
2021	77.305
2022	76.939