Year % of children ages 12-23 months 1980 9.527634971514129 1981 15.741594952954351 1982 19.043226728910614 1983 21.433327195367976 1984 22.69117806610844 1985 28.629142592285604 1986 36.15409014297992 1987 38.84760542179443 1988 44.45220543584102 1989 48.44327767739681 1990 52.507268119210345 1991 46.257380343474075 1992 45.848211801111454 1993 47.81257290823235 1994 53.75015808883193 1995 52.46520817214509 1996 53.3639027923335 1997 51.75170256386211 1998 49.874450005362355 1999 50.33885124149978 2000 54.478439308290106 2001 55.0066572259354 2002 57.27167037523457 2003 60.93360385917823 2004 63.20579430759651 2005 65.89953428102787 2006 68.13615714682165 2007 69.93655119801598 2008 69.95945387713175 2009 72.7535595792214 2010 74.69617281722111 2011 74.77710818207163 2012 75.63881384855789 2013 74.12969628286491 2014 73.76128735364844 2015 73.55890965698964 2016 72.55103855335244 2017 73.80778215896639 2018 73.4474301776123 2019 73.5424676333595 2020 71.87147787994756 2021 69.4035296278792 2022 70.13324298659487