Year	Percent
1991	61.369
1992	62.047
1993	63.044
1994	63.533
1995	63.057
1996	63.11
1997	63.306
1998	63.258
1999	63.074
2000	63.076
2001	62.403
2002	61.95
2003	62.152
2004	61.598
2005	61.649
2006	61.132
2007	60.921
2008	59.569
2009	58.94
2010	59.907
2011	59.732
2012	59.395
2013	59.351
2014	59.457
2015	58.888
2016	58.88
2017	58.762
2018	58.661
2019	58.564
2020	58.46
2021	58.299
2022	58.083