In consideration of premium by policy being provisional subject to adjustment on expiry of each period of insurance the insured agrees to declare in writing the value of the stocks (other than retail) less any amount insured by policies other than declaration policies, in each separate building or non-communicating compartment or in the open on the following basis namely (1) average of the values at the risk on each day of the month, or (2) The highest value at risk during the month and to make such declarations by the last date of the succeeding month. In respect of a declaration not being made as stipulated the insured shall be deemed to have declared the sum insured hereby as the value at risk. On expiry the premium shall be calculated on the average sum insured and if the resultant premium is less than the provisional premium the different shall be repaid to the insured buy such repayment shall not exceed 50% of the provisional premium. No reduction in sum insured to be allowed mid-term. Basis of value for declaration shall be the market value and any loss shall be settled on the basis of market value immediately anterior to the loss. Midterm cancellation by insured the premium to be retained shall be the appropriate short premium calculated on the average amount insured up to the date of concealment or 50% of the provisional premium whichever is greater. If cancellation by insurer premium to be retained shall be the appropriate pro-rata premium calculated on the average amount insured up to the date of concealment or 50% of the provisional premium whichever is greater.