Year	Percent
1991	65.46
1992	65.366
1993	65.127
1994	65.531
1995	67.781
1996	67.156
1997	65.942
1998	67.46
1999	70.195
2000	71.797
2001	70.998
2002	70.06
2003	68.942
2004	69.472
2005	69.11
2006	69.323
2007	69.919
2008	69.075
2009	66.267
2010	65.881
2011	65.858
2012	66.83
2013	67.85
2014	68.692
2015	70.135
2016	70.941
2017	70.841
2018	70.438
2019	70.012
2020	69.562
2021	69.127
2022	68.688