Year	Percent
1991	77.016
1992	77.092
1993	77.274
1994	73.363
1995	71.198
1996	69.694
1997	69.31
1998	69.127
1999	68.687
2000	68.791
2001	69.705
2002	70.283
2003	70.147
2004	69.868
2005	70.151
2006	70.369
2007	70.79
2008	71.484
2009	71.223
2010	72.101
2011	72.418
2012	72.928
2013	72.821
2014	73.566
2015	73.88
2016	74.036
2017	74.122
2018	73.938
2019	73.624
2020	73.177
2021	72.517
2022	71.743