WBEZ brings you fact-based news and information. Sign up for our newsletters to stay up to date on the stories that matter.It’s the 20th day of school for Chicago Public Schools, which is the day it traditionally takes its official enrollment count. But this year is a little different than most. For the first time since 1970, CPS enrollment has dropped below 400,000. WBEZ’s education reporter Becky Vevea discusses why Chicago Public Schools have been facing a decline in enrollment rates.