Year	Percent
1991	77.303
1992	76.706
1993	76.8
1994	77.017
1995	76.761
1996	76.466
1997	77.08
1998	76.568
1999	74.825
2000	75.352
2001	74.928
2002	72.836
2003	72.08
2004	71.724
2005	72.331
2006	73.704
2007	74.653
2008	74.226
2009	74.159
2010	74.829
2011	74.665
2012	74.934
2013	74.7
2014	74.943
2015	76.036
2016	75.651
2017	75.233
2018	75.122
2019	74.944
2020	74.531
2021	74.116
2022	73.693