Year	Percent
1991	76.044
1992	76.082
1993	76.087
1994	75.853
1995	75.581
1996	75.249
1997	74.83
1998	74.27
1999	73.593
2000	72.718
2001	71.874
2002	70.885
2003	69.854
2004	68.698
2005	67.668
2006	67.047
2007	66.407
2008	65.966
2009	65.696
2010	65.456
2011	65.232
2012	65.047
2013	64.903
2014	64.76
2015	64.643
2016	64.373
2017	64.506
2018	64.61
2019	64.69
2020	64.75
2021	64.782
2022	64.799