Year	Percent
1991	57.991
1992	58.618
1993	59.068
1994	58.927
1995	58.179
1996	58.653
1997	57.966
1998	59.165
1999	60.11
2000	61.322
2001	61.431
2002	61.113
2003	61.384
2004	62.698
2005	62.857
2006	62.839
2007	62.75
2008	63.082
2009	63.706
2010	64.861
2011	64.434
2012	64.778
2013	64.645
2014	64.465
2015	65.319
2016	66.127
2017	66.157
2018	66.161
2019	66.161
2020	66.241
2021	66.33
2022	66.386