Year	Percent
1991	71.969
1992	72.357
1993	71.899
1994	72.946
1995	73.546
1996	73.593
1997	73.251
1998	68.645
1999	68.513
2000	70.05
2001	70.193
2002	71.448
2003	71.199
2004	71.43
2005	71.029
2006	70.746
2007	70.798
2008	70.173
2009	69.278
2010	69.285
2011	69.616
2012	69.937
2013	70.002
2014	70.634
2015	70.417
2016	70.383
2017	70.338
2018	70.345
2019	70.392
2020	70.265
2021	70.109
2022	69.916