don't worry about the maths not adding up. I understand where you are coming from. "Modern" forms of crime like what you mentioned and cyber-crime, car crime etc will always skew the figures. It is difficult territory. Also population density will affect the figures. so if the population of a city doubles you can assume crime will (more-than-)double. I wonder if there is a way to filter out those factors and just focus on good 'ld fashioned age-defying crimes like: Stealing, stabbings, rape, burglary, murder etc....