Year	Percent
1991	71.073
1992	71.386
1993	71.153
1994	70.409
1995	70.03
1996	69.053
1997	68.938
1998	68.897
1999	68.696
2000	68.911
2001	68.777
2002	65.64
2003	67.399
2004	68.322
2005	70.442
2006	71.463
2007	71.207
2008	70.72
2009	70.06
2010	70.715
2011	71.223
2012	71.003
2013	70.804
2014	69.763
2015	70.623
2016	70.832
2017	71.005
2018	71.111
2019	71.125
2020	70.995
2021	70.722
2022	70.362