Year % of children ages 12-23 months 1980 1 1981 1 1982 2 1983 3 1984 4 1985 8 1986 14 1987 27 1988 40 1989 60 1990 62 1991 62 1992 53 1993 51 1994 46 1995 48 1996 56 1997 55 1998 46 1999 55 2000 62 2001 66 2002 60 2003 69 2004 74 2005 78 2006 78 2007 84 2008 86 2009 81 2010 90 2011 93 2012 92 2013 93 2014 94 2015 93 2016 93 2017 95 2018 93 2019 93 2020 90 2021 84 2022 84