Year	Percent
1991	79.932
1992	79.781
1993	78.54
1994	76.724
1995	76.344
1996	75.896
1997	74.621
1998	75.826
1999	70.908
2000	69.614
2001	71.163
2002	70.578
2003	72.351
2004	74.076
2005	74.726
2006	73.77
2007	73.51
2008	72.584
2009	71.84
2010	72.795
2011	69.319
2012	68.089
2013	69.26
2014	71.875
2015	72.123
2016	73.027
2017	72.666
2018	72.125
2019	71.655
2020	71.291
2021	70.966
2022	70.675