Upon every person engaging or continuing within the City in the business of producing for sale, profit or commercial use any natural resource product, the amount of such tax shall be equal to the value of the articles produced as shown by the gross proceeds derived from the sale thereof by the producer, except as hereinafter provided, multiplied by the respective rates as follows: Coal, one percent (1%); limestone or sandstone, quarried or mined, one and fifty one-hundredths percent (1.50%); oil, three percent (3%); natural gas in excess of the value of five thousand dollars, six percent (6%); sand, gravel or other mineral product, not quarried or mined, three percent (3%); timber, one and fifty one-hundredths percent (1.50%); other natural resource products, two percent (2%). The measure of this tax is the value of the entire production in the City, regardless of the place of sale or the fact that delivery may be made to points outside the City.