Year	Percent
1991	66.844
1992	64.875
1993	64.462
1994	65.027
1995	65.212
1996	64.843
1997	65.355
1998	65.798
1999	66.541
2000	67.118
2001	66.596
2002	66.83
2003	67.37
2004	67.479
2005	67.491
2006	67.413
2007	67.744
2008	67.817
2009	64.933
2010	65.162
2011	65.611
2012	65.46
2013	65.479
2014	65.251
2015	65.198
2016	64.723
2017	65.099
2018	65.19
2019	64.903
2020	64.584
2021	64.232
2022	63.855