How much Latin does the Vatican use on a day-to-day basis?

The 1985 letter from Cardinal Ratzinger in Latin seems to be stirring up some discussion online over whether the Vatican conducts all its business in Latin or not, and in response to that Slate released an article today on that very subject. There probably isn't any new information there for Page F30 readers, but it's well-sourced and may be worth bookmarking for later or sending to someone you know.