Year % of children ages 12-23 months 1981 22 1982 21 1983 20 1984 18 1985 17 1986 27 1987 38 1988 49 1989 51 1990 52 1991 54 1992 56 1993 57 1994 59 1995 57 1996 55 1997 54 1998 50 1999 55 2000 57 2001 59 2002 62 2003 64 2004 66 2005 68 2006 75 2007 75 2008 70 2009 77 2010 73 2011 75 2012 80 2013 83 2014 85 2015 79 2016 79 2017 83 2018 86 2019 87 2020 89 2021 90 2022 90