Year	Percent
1991	66.48
1992	64.06
1993	62.45
1994	62.799
1995	63.456
1996	63.447
1997	64.465
1998	65.03
1999	65.184
2000	65.645
2001	65.587
2002	65.199
2003	65.571
2004	65.577
2005	65.67
2006	65.502
2007	65.488
2008	65.287
2009	63.06
2010	62.685
2011	62.391
2012	62.788
2013	62.958
2014	63.913
2015	64.469
2016	64.817
2017	65.089
2018	65.266
2019	65.231
2020	65.032
2021	64.786
2022	64.519