Year	% (national estimate)
1960	29.333544403989237
1990	67.32673267326732
1991	67.109634551495
1992	65.09852900360809
1993	65.6320224719101
1994	67.8652321630804
1995	67.20658888126287
1996	69.54752804832943
1997	69.80507070964454
1998	70.56086844145774
1999	73.42931937172774
2000	75.66737853710625
2001	76.21805363212891
2002	77.70577691989521
2003	76.59942363112391
2004	78.16157579217813
2005	80.22303783173348
2006	80.01359619306595
2007	82.5
2008	83.10915675116401
2009	85.16856813229072
2010	85.12311460616219
2011	86.39508070714834
2012	84.99045194143858
2013	86.12775723575162
2014	85.31696316712603
2015	85.54731682795023
2016	86.53895602982772
2017	87.23684210526315
2018	88.62433862433863
2019	89.41018766756034
2020	89.18558077436582