Year	Percent
1991	84.757
1992	83.393
1993	83.048
1994	81.468
1995	73.898
1996	73.558
1997	73.059
1998	73.493
1999	72.618
2000	71.9
2001	70.864
2002	69.53
2003	68.843
2004	68.825
2005	68.781
2006	67.782
2007	74.023
2008	73.85
2009	73.21
2010	68.258
2011	69.715
2012	69.031
2013	70.184
2014	69.616
2015	71.511
2016	71.477
2017	71.56
2018	71.447
2019	71.407
2020	71.379
2021	71.357
2022	71.354