Fellow Diamond solo-queue people

Ok, so I have been wondering about this. Getting RP as a solo-queue is pretty hard. Sometimes you play for 2 or 3 hours and at the end, you are right back where you started! So my question is: How much RP you usually get per hour(in plat lobbies)? Or say you play for 3 hours(or however long you play for), how much RP do you usually get? 

I play for like 3-4 hours and get like 250-300 RP. Is that too low? I just wanted to see how I fare against other peeps here.

This question is strictly for solo-queuers. But you can share how much you get as a pre-made team too.