Year	Percent
1991	85.451
1992	84.484
1993	82.935
1994	81.027
1995	79.375
1996	78.965
1997	78.968
1998	79.444
1999	79.92
2000	80.014
2001	79.639
2002	78.993
2003	78.029
2004	77.107
2005	76.486
2006	76.073
2007	75.929
2008	75.885
2009	75.809
2010	75.478
2011	75.078
2012	74.536
2013	75.154
2014	75.655
2015	75.194
2016	74.63
2017	74.445
2018	74.299
2019	74.156
2020	73.994
2021	73.823
2022	73.64