"Figure 4: The majority of unexplained infant deaths occur in the postneonatal period","" "Percentage of unexplained deaths by age at death, England and Wales, 2004 to 2020p","" "","" "Notes","1. Proportions may not sum to 100% because of rounding." "Unit","Proportion (%)" "","" "","Postneonatal","Neonatal" "2004","77.5","22.4" "2005","82.1","17.8" "2006","79.6","20.4" "2007","89.7","10.3" "2008","78.8","21.3" "2009","80.8","19.1" "2010","84.7","15.3" "2011","79.4","20.6" "2012","82.9","17.1" "2013","82.6","17.5" "2014","83.9","16.1" "2015","80.5","19.5" "2016","81.1","19.0" "2017","82.0","18.0" "2018","82.7","17.4" "2019","81.4","18.7" "2020p","84.1","16.0"