Year	Percent
1991	76.103
1992	76.044
1993	76.424
1994	76.301
1995	76.036
1996	76.304
1997	76.263
1998	76.17
1999	75.939
2000	76.086
2001	75.612
2002	75.432
2003	75.132
2004	74.992
2005	74.912
2006	74.779
2007	74.452
2008	73.887
2009	73.447
2010	73.762
2011	74.438
2012	75.021
2013	75.323
2014	75.187
2015	75.115
2016	74.73
2017	74.95
2018	75.178
2019	75.355
2020	75.471
2021	75.544
2022	75.589