By: Mark Glennon*   Compensation for firefighters and police is the third rail nobody wants to talk about. The key numbers are below, including what happened over the last thirty years.   Both the police and firefighter pensions have only about one-forth of the assets they should have to pay benefits promised — officially, that is. The real numbers are worse and we will be writing separately about that.   There’s good reason why most of us lay off the subject of compensation for police and fire. I admit to some bias, too. My relatives include lots of the