Amid a national push to reduce screen time in schools, elementary and middle school students report less of their free time is spent reading. The share of 13-year-olds who read for fun has declined by nearly half since 2012, according to survey data published Wednesday by the Education Department’s National Center for Education Statistics . The share of 9-year-olds — the other age group studied — who read for fun has declined 16 percentage points in the past 13 years. Students reading for