Year	% of children ages 12-23 months
1981	15
1982	34
1983	30
1984	29
1985	29
1986	28
1987	28
1988	27
1989	27
1990	35
1991	42
1992	52
1993	55
1994	58
1995	61
1996	61
1997	56
1998	52
1999	40
2000	42
2001	44
2002	46
2003	48
2004	50
2005	51
2006	51
2007	57
2008	55
2009	53
2010	58
2011	62
2012	58
2013	54
2014	50
2015	47
2016	47
2017	47
2018	47
2019	47
2020	47
2021	47
2022	47