Year	Percent
1991	65.455
1992	64.673
1993	65.127
1994	65.008
1995	64.58
1996	64.584
1997	63.047
1998	63.082
1999	63.085
2000	64.025
2001	64.026
2002	59.686
2003	59.685
2004	60.763
2005	60.762
2006	59.955
2007	59.388
2008	60.486
2009	59.3
2010	59.247
2011	58.776
2012	56.302
2013	56.146
2014	56.499
2015	56.491
2016	57.164
2017	57.193
2018	57.122
2019	57.05
2020	56.976
2021	56.902
2022	56.828