Year	Percent
1991	64.983
1992	64.433
1993	63.91
1994	64.83
1995	64.976
1996	67.265
1997	69.051
1998	70.329
1999	70.043
2000	70.217
2001	69.696
2002	69.162
2003	67.674
2004	67.226
2005	67.099
2006	68.034
2007	69.003
2008	69.726
2009	67.837
2010	66.841
2011	66.449
2012	66.551
2013	65.977
2014	65.554
2015	65.304
2016	64.191
2017	64.502
2018	64.51
2019	64.362
2020	64.182
2021	63.944
2022	63.694