Year	Percent
1991	88.353
1992	87
1993	84.782
1994	81.973
1995	79.469
1996	78.76
1997	79.01
1998	79.968
1999	80.89
2000	81.215
2001	80.77
2002	79.869
2003	78.427
2004	77.133
2005	76.357
2006	75.972
2007	76.087
2008	76.469
2009	76.688
2010	76.517
2011	76.19
2012	75.53
2013	75.637
2014	75.642
2015	74.917
2016	74.091
2017	73.903
2018	73.778
2019	73.648
2020	73.477
2021	73.285
2022	73.067