Year % of children ages 12-23 months 1980 0.2995197480169954 1981 0.2588176990049641 1982 0.5817671539350531 1983 2.49295487208837 1984 4.450597056582902 1985 6.204582908326196 1986 13.79309068622664 1987 25.10286138598543 1988 32.6638400041465 1989 44.23754265996397 1990 55.959654672813514 1991 46.82561410609573 1992 52.89986886922381 1993 59.17598430201244 1994 65.67861784416304 1995 68.58672740180872 1996 63.88745875184438 1997 56.54319200026681 1998 54.9805784546268 1999 57.68931531546955 2000 57.85224662036313 2001 59.36650306001226 2002 58.52644157505324 2003 61.90395885254699 2004 65.52375502875314 2005 68.8373892723774 2006 69.0369445123457 2007 69.93573006188333 2008 71.47295592643248 2009 75.8921683232144 2010 78.33624444111098 2011 80.45785467856577 2012 79.68931500110416 2013 80.64265889203195 2014 82.80985521269021 2015 85.07432308593965 2016 85.75909125773364 2017 87.51326288306656 2018 90.19740710930145 2019 91.61450721563081 2020 87.80939592548157 2021 87.36341813284326 2022 91.72149195148185