Year	Percent
1991	78.669
1992	78.345
1993	78.354
1994	78.289
1995	78.136
1996	78.104
1997	77.391
1998	77.09
1999	79.279
2000	78.982
2001	78.756
2002	78.524
2003	78.432
2004	78.343
2005	77.953
2006	75.055
2007	74.484
2008	74.465
2009	74.176
2010	73.381
2011	66.45
2012	65.818
2013	65.17
2014	64.533
2015	64.051
2016	63.721
2017	63.63
2018	63.51
2019	63.402
2020	63.295
2021	63.19
2022	63.085