Year	Percent
1991	65.757
1992	65.7
1993	65.625
1994	65.598
1995	65.198
1996	64.821
1997	64.052
1998	62.644
1999	61.167
2000	63.729
2001	66.284
2002	68.848
2003	71.298
2004	73.599
2005	73.445
2006	73.325
2007	73.231
2008	73.188
2009	72.962
2010	72.845
2011	72.83
2012	73.057
2013	73.286
2014	73.472
2015	73.604
2016	73.725
2017	74.07
2018	74.394
2019	74.702
2020	74.992
2021	75.262
2022	75.515