In the event of Gross Profit earned (or proportionately increased multiple thereof where the maximum Indemnity period exceeds twelve months) during the accounting period most nearly concurrent with any period of insurance as certified by the Insured’s Auditors, being less than the sum insured thereon, a prorata return of premium not exceeding 50 percent of the premium paid on such sum insured for such period of insurance will be made in respect of the difference. If any damage shall have occurred giving rise to a claim under this Policy, such return shall be made in respect only of so much of the said difference as is not due to such damage. Any application for return of premium shall be made by the Insured within 6 (six) months from the date of expiry of the policy.