Variable is not getting set every time this While loop runs?

Ok, I know ive done this before but I cant find where,

while FuelLelf == true do
		print(CurrentFuel)
		local CurrentFuel = CurrentFuel - FuelDecreaseNum 
		print(CurrentFuel)
		wait(.3)
	end

In my mind, because that's happening, and every time CurrentFuel is being decreased, every time it runs the fuel will be a lower number than the last time it ran. However, I only get "100 90 100 90" in the output. So im not sure what's happening.