What BBM giveth, PPM taketh. The Rick Mercer Report was up to 1,242,000 viewers Tuesday night while CBC’s much hyped The National slipped to 627,000 at 10 and 495,000 at 10:25. The other newscasts all held steady: CTV National News at 11 got 1,328,000. Global National at 5:30 scored 1,209,000. Other Tuesday night numbers in