I still bet it’s a bit more than 4–5 million, but probably not more than ten. Even at Yara’s plants, North Rail has separate shunting locomotives in both Siilinjärvi and Uusikaupunki. You don’t just bring and take cargo with a line-haul locomotive (though, admittedly, you don’t need a separate shunter in Harjavalta).
Of course, one could try to calculate it roughly since we know the transport routes and volumes; it was 32 million last year, but a bit less the year before at 28 million, and 24 million the year before that.
Well, it’s unlikely that North Rail leases its equipment to others, even though they themselves seem to have those two most recently arrived Dr21 locomotives as leased rolling stock from Operail. I don’t think North Rail owns any wagons at all, and the ownership of the wagons is probably somewhere in Russia.