Year	Percent
1991	63.977
1992	62.765
1993	61.855
1994	61.062
1995	60.279
1996	60.061
1997	60.604
1998	61.137
1999	62.019
2000	64.752
2001	67.129
2002	68.114
2003	67.778
2004	67.124
2005	66.991
2006	65.761
2007	65.531
2008	65.16
2009	65.923
2010	65.682
2011	64.259
2012	63.285
2013	62.825
2014	63.177
2015	62.917
2016	62.807
2017	63.206
2018	63.18
2019	63.147
2020	63.11
2021	63.068
2022	63.023