There was a triable issue of fact as to how to compute the amount of income lost due to a covered event–the theft of the insured’s inventory–over what period the average pre-loss income should be measured and the amount of income that would have been earned but for the covered loss. However, the insured was not entitled to recover for additional expenses it incurred to resume business as quickly as possible (thus mitigating its covered business loss) because under the policy it was obliged to resume business as soon as possible.