Year	Percent
1991	75.611
1992	75.145
1993	75.347
1994	75.844
1995	76.158
1996	75.981
1997	75.974
1998	76.061
1999	75.934
2000	75.788
2001	75.594
2002	75.432
2003	75.281
2004	75.139
2005	74.943
2006	74.863
2007	74.736
2008	74.608
2009	74.495
2010	74.383
2011	74.263
2012	74.209
2013	74.176
2014	74.026
2015	73.903
2016	73.764
2017	73.772
2018	73.768
2019	73.755
2020	73.738
2021	73.726
2022	73.713