The 'rate' applied by underwriters at the next renewal for AF will reflect the overall market trend. If it has been a bad year overall for aviation then a rate increase can be expected, not just for AF but across the board, if it has been a good year then the rate will, at least, remain unchanged and possibly even be reduced.
When establishing the rate the leading underwriters first look to see 'what is in the pot', in other words what has been the premium income over the last, say, ten years, compared to the claims. If you know the fleet value for an airline and then take, say, .4% of that you are looking at their annual premium, in the case of AF they probably have quite a bit in credit with the underwriters, despite Concord, and won't be expecting an increase at their next renewal.