I calibrate my CRT every 2-3 weeks with Monaco EZcolor. The past few calibrations I've noticed that the brightness settings I'm having to use to get the calibration to spec has used a gradually increasing number. For a few years, the correct brightness setting was round 76-77. Then it crept up to around 82, and recently it's started to need 86-87 for proper calibration. Does this mean I may be needing a new monitor before too long? The monitor is a 21" IBM, with Sony Trinitron tube.