No idea. I cycle in Germany I would argue that the main issue is extremely aggressive and reckless behavior towards cyclists by car drivers, not that they're inattentive. Although that's a big problem as well, many drivers simply don't "look" for cyclists - you always need to act like you don't have right of way. Of course, many drivers get aggressive against cars as well, e.g. somewhat adhering to traffic laws is a surefire way of inciting road rage.
I'd argue that a lot of deadly accidents in the city are inattention and lack of suitable infrastructure - if you look at the statistics in Berlin for example, the common pattern for deadly accidents is (right-)turn crossing a cycle lane and crushing a cyclist. Still, dedicated right-turn lanes with a crossing cycling path are still built, traffic lights still allow right-turns while allowing straight through cycle traffic. Changes get made - if at all - after a deadly accident, sometimes it takes multiple. Suitable infrastructure is certainly not the only thing that's missing, but the current lack of it, combined with lackluster removal of parked vehicles on the bit that exists are a major driver or deadly incidents.
if the epidemic of cell phone use while (badly) driving where i live is any indication, it’s a very large share.