Year	Percent
1991	64.849
1992	64.464
1993	64.101
1994	63.667
1995	63.372
1996	63.081
1997	63.671
1998	63.473
1999	63.807
2000	64.154
2001	64.665
2002	65.156
2003	65.564
2004	65.597
2005	65.241
2006	64.889
2007	64.276
2008	64.567
2009	64.857
2010	64.373
2011	64.64
2012	65.186
2013	65.913
2014	66.444
2015	66.846
2016	67.234
2017	67.196
2018	67.17
2019	67.147
2020	67.116
2021	67.095
2022	67.065