percentage of depletion allowance method

To develop an oil well containing 2,000,000 barrels of oil required an initial investment of PhP 30,000,000.00. In a certain year, 400,000 barrels of oil were produced from this well.

The total gross income of the oil company is PhP 34,000,000.00 for the particular year, and the taxable income after talking all deductions, except for depletion, is PhP 14,100,000.00. Determine the allowable depletion allowance for the year.