I like to look at new cases by age group to look for trends. For example, in mid-late June, cases among 20-somethings started to skyrocket. But cases also rose substantially for kids and other age groups.
But I was still shocked to see the current new case data for the 10-19 age group.
Starting in September cases for this age group have risen substantially. Since this age group goes through 19, I wonder if the rise in cases is driven by college students who have returned to campus. We know that SDSU has had several hundred new cases since late August (although driven by behavior outside of classes, since most classes resumed online).
To see new cases for all age groups since April 1, 2020, see http://cv19.shulok.com/2020/09/09/case-rate/.