Year	Percent
1991	67.36
1992	66.706
1993	67.188
1994	67.423
1995	67.407
1996	67.114
1997	67.291
1998	67.261
1999	67.039
2000	67.096
2001	67.009
2002	66.588
2003	66.269
2004	66.637
2005	66.381
2006	66.653
2007	66.504
2008	66.479
2009	66.416
2010	66.069
2011	65.656
2012	64.885
2013	64.23
2014	63.934
2015	64
2016	64.167
2017	64.528
2018	64.181
2019	63.842
2020	63.724
2021	63.165
2022	62.542