Playback time relative to song’s length

Right now in the stats tab we can sort the songs by the playback count or the playback time. I think it would be really useful to introduce a way of sorting them by (total song playback time) divided by (song length), or as an option to the existing sort by playback time. It would never be more than the playback count, but it would be even more precise with songs that are longer than usual popping up really high in the playback time chart despite having listened to them only once.