Year	Percent
1991	74.229
1992	74.979
1993	74.88
1994	74.021
1995	74.059
1996	74.221
1997	74.667
1998	69.786
1999	70.106
2000	69.459
2001	70.594
2002	71.598
2003	72.571
2004	72.263
2005	72.258
2006	71.946
2007	71.535
2008	70.672
2009	69.957
2010	69.41
2011	69.628
2012	69.745
2013	69.667
2014	69.488
2015	70.692
2016	71.265
2017	71.594
2018	71.558
2019	71.524
2020	71.498
2021	71.477
2022	71.458