Year	Percent
1991	71.677
1992	71.65
1993	71.65
1994	71.615
1995	71.547
1996	71.484
1997	70.702
1998	71.12
1999	71.089
2000	71.086
2001	70.679
2002	71.122
2003	70.971
2004	70.794
2005	70.638
2006	70.508
2007	70.367
2008	70.532
2009	70.305
2010	70.57
2011	71.338
2012	71.901
2013	72.147
2014	72.55
2015	71.914
2016	71.77
2017	71.843
2018	71.779
2019	71.663
2020	71.504
2021	71.312
2022	71.073