Just wondering if the 6 months pay slips we need to submit all have to show that you are earning over £18,600, or do they have to average that?

Started my new job in March on the training rate of approx £18,200, which last month raised to £18,800 and was backdated to April, but as of yesterday I was fully qualified so now earn approx £22k. Obviously the 6 months of pay slips from March will average well over the required amount, especially since the backdated raise.

Just need to know if I can apply including those under the amount as well, or if we have to wait even longer. Would the backdating cut that time down if we have to wait too?