| Ah — looking up the source, the train data seems to come from here http://www.nationmaster.com/graph/tra_rai_pas_car_mil_pas_percap-million-passenger-km-per-capita so it is indeed per capita — so it’s actually in “million passenger-km per million inhabitants”, or more simply put, “km per capita”. (Actually, I presume it should be “km per capita per year”, though the source doesn’t say so.) |