Out of morbid curiosity I’m looking to calculate the yearly probability that someone (politician, actor, tv host or guest, news correspondent, etc) would have a stroke or heart attack on live TV. In order to make a back-of-the-envelope calculation I would at least need to know the total number of person-hours per year on live TV (ideally per gender and age group, but for an order-of-magnitude estimate that isn’t necessary). The question could also be expanded beyond ‘live TV’ to ‘time spent on camera.’ Is this a known figure? How about the total number of hours of live TV in the US per year, or the totally number of hours of commercial film or television footage recorded each year?