Year	Percent
1991	58.421
1992	58.615
1993	61.138
1994	61.772
1995	64.598
1996	65.902
1997	64.197
1998	64.509
1999	66.658
2000	67.964
2001	69.104
2002	71.439
2003	69.481
2004	67.365
2005	66.558
2006	66.037
2007	65.107
2008	64.954
2009	65.691
2010	65.572
2011	65.701
2012	65.986
2013	65.132
2014	64.389
2015	64.922
2016	65.113
2017	65.554
2018	65.67
2019	65.793
2020	65.908
2021	65.997
2022	66.069