Year	Percent
1991	52.439
1992	52.189
1993	52.23
1994	52.968
1995	53.618
1996	55.356
1997	56.839
1998	58.725
1999	59.178
2000	59.256
2001	59.312
2002	59.84
2003	58.598
2004	58.774
2005	58.17
2006	58.99
2007	60.566
2008	61.749
2009	60.998
2010	59.973
2011	59.818
2012	59.978
2013	59.579
2014	59.369
2015	58.875
2016	58.502
2017	58.589
2018	58.699
2019	58.687
2020	58.628
2021	58.535
2022	58.429