The logo of Exxon Mobil Corporation is shown on a

FILE PHOTO: The logo of Exxon Mobil Corporation is shown on a monitor above the floor of the New York Stock Exchange in New York, December 30, 2015. Standard & Poor’s Ratings Services said on April 26, 2016, it had cut Exxon Mobil Corp’s corporate credit rating to “AA+” from “AAA,” citing the impact of low oil prices. REUTERS/Lucas Jackson