Year	Percent
1991	71.929
1992	72.007
1993	72.144
1994	72.23
1995	72.382
1996	72.439
1997	72.46
1998	72.493
1999	72.489
2000	72.433
2001	72.328
2002	72.183
2003	72.012
2004	71.826
2005	71.637
2006	71.402
2007	71.185
2008	70.986
2009	70.801
2010	70.607
2011	70.405
2012	70.213
2013	70.053
2014	69.944
2015	69.896
2016	69.918
2017	69.978
2018	70.077
2019	70.177
2020	70.271
2021	70.358
2022	70.44