What are talking about? I do not care of overall diff raise, it is absolutely clear and inevitably.
But about bad luck will be never covered with such raise now +10% per 2 weeks. It is 90% for last months here.
What's past is past. What matters is whether or not pool performance will continue to be poor. If you believe the recent performance reflects bad luck then the best bet may be to stay. If you think some other reason accounted for the poor performance then it may be a better bet to move elsewhere. Moving to another pool without a good reason may prove, with the benefit of hindsight, to have been a poor decision.
You can probably get better odds if you solo mine or use a good solo mining pool. At least you won't be subject to block withholding attacks. However, this won't be an good choice if you don't have a lot of resources to pay your electricity bills, buy new miners if they become obsolete before you hit the jackpot, etc... because of the "gambler's ruin problem".