This Article was repealed by Royal Decree M/70 of 1439H, effective from 1 January 2018. It previously outlined the method for determining the Natural Gas Investment Tax (NGIT) rate for any taxable year. The rate was directly linked to the internal rate of return (IRR) on a taxpayer's cumulative annual cash flows from natural gas investments. A detailed table specified the tax percentages, which ranged from 30% for an IRR of 8% or less, increasing progressively to 85% for an IRR of 20% or higher. The Article also defined 'cumulative annual cash flows' and 'internal rate of return'.