There's no denying that QR and EY have had an effect on EK at GLA - that was inevitable. That said, EK has only seen decreases of a few % at the very most (less than 1% in April) which typically equates to a few hundred pax. In other words, it's somewhat stagnant.
That said, look how cheap QR are in comparison to EK a lot of the time, one has to wonder if it's generating as much money as it should be, in which case EK losing a few hundred pax is nothing to lose sleep over, especially when there are 32 first class seats between GLA and DXB every day for a thousands of £ each. All of this doesn't take cargo in to account, however.
As for DOH-EDI vs DOH-USA, is that really a fair comparison?
VickersViscount, to answer your question, 64% in April 2016 based on the CAA figures.