https://www.sciencedaily.com/releases/2014/06/140617102503.htm
Early elementary school start times tougher on economically advantaged children | ScienceDaily
Middle- and upper-class elementary school students demonstrated worse academic performance when they were required to start classes early, compared to peers...
early elementary schoolstart times
https://www.illinoisreportcard.com/School.aspx?source=environment&source2=earlylearning_studentsmeasured&Schoolid=440630470042011
GLACIER RIDGE ELEMENTARY SCHOOL | Early Learning : % of Students Measured
glacier ridgeelementary schoolearly learningstudentsmeasured