Year	% (national estimate)
1970	35.89743589743589
1975	43.96671289875173
1976	46.41355586698943
1977	48.18343495934959
1978	50.28814833375095
1979	51.9087754090233
1980	54.7804576376005
1982	55.45198086593892
1983	55.96667483459936
1984	56.472471979307805
1985	56.13815542485297
1986	57.49212350346566
1987	59.70244150559512
1988	60.89449541284403
1989	61.62361623616236
1991	61.854996734160686
1992	59.258743207468314
1993	57.868233319345364
1994	59.00084913671101
1995	61.959208899876394
1996	59.897735573411246
1997	60.62944469662581
1998	60.9129147842343
1999	65.14586814034186
2000	70.35367545076284
2001	66.40494272107092
2002	65.53108808290156
2003	66.90760940990931
2004	67.77645659928656
2005	69.89247311827957
2006	71.20357002231265
2007	69.41284163724336
2008	73.10372025765743
2009	72.33149750852347
2010	73.80392156862744
2011	75.31729243786356
2012	75.92787575677809
2013	76.6490765171504
2014	77.23919915700738
2015	78.76417676965194
2016	79.25964820162773
2017	78.73124506449065
2018	79.57699933906146
2019	81.07176018039527
2020	81.14884584770496
2021	83.1626833946809
2022	82.29564404270239