article_snippet.sent: The CDC report, released on Thursday, is based on a national survey of about 22,000 students at middle schools and high schools, both public and private.
article_snippet.sent: Tom Frieden, CDC director, remarked that the results are 'alarming' and 'shocking'. '
highlights_snippet.sent: That is an increase of 13 per cent from the 660,000 recorded in 2013 .
  