Year	Percent
1991	62.462
1992	62.62
1993	62.712
1994	62.681
1995	62.492
1996	60.425
1997	58.767
1998	56.281
1999	55.343
2000	55.966
2001	55.258
2002	55.829
2003	55.969
2004	56.753
2005	58.208
2006	57.911
2007	58.144
2008	58.127
2009	56.326
2010	57.107
2011	57.978
2012	58.449
2013	59.048
2014	56.214
2015	56.916
2016	56.48
2017	56.186
2018	56.312
2019	56.326
2020	56.238
2021	55.955
2022	55.586