BBC reporting oil at a near 4 year low, and BA originally responded to high oil prices by introducing/increasing YQ - so why havent they reduced YQ

Seems to me that BA are behaving like the UK government - once a tax/charge is established it is very rarely reduced and even more rare, removed.

i know some of you will come back and say BA have hedged and therefore may be paying more but seriously they seem to quickly react to increasing prices but more reluctant to reduce the charge when prices go the other way.