Findlay, OH-Based Oil & Gas Co Marathon Petroleum Corp 4Q 2017 Net Income Was $2,125 Mil, Up 635% or Up By $1,836 Mil From the 4Q 2016 Net Income of $289 Mil .................................................................................. $1,500 Mil or 82% of the $1,836 Mil Net Income Improvement Came From an Income Tax Benefit From the US Federal Income Tax Debt Forgiveness Feature in the Oil & Gas Industry-Favored Trump Tax Bill