For purposes of this Article, "Steel $" shall be defined as the dollar amount of the Contract Base Price identified as "Steel Materials". Economic Price Adjustments for Steel shall be calculated using the American Metal Market (AMM) Monthly Domestic Prices for Carbon Steel Plate Cut to Length (“AMM Index”). The "Current Period" is defined as the 3 month period commencing with the month four months prior to the estimated start of construction milestone as set forth in a notice to Purchaser from Contractor for each Vessel. The "Current Period Index" is defined as the arithmetic average of the monthly values of the AMM Index published for the Current Period. The Base Price Index is $[***] per hundred pounds, or centum weight ($/cwt), which is the value of the AMM Index [***], the price used to calculate Steel $ and the Base Contract Price at the time this Contract was formed.