(FILES) This file photo taken on February 16, 2017 shows Co-chair of the Bill & Melinda Gates Foundation Bill Gates as he addresses a press conference after meeting European Commission foreign policy chief Federica Mogherini at the European Commission in Brussels. Microsoft co-founder Bill Gates once again topped the Forbes magazine list of the world's richest billionaires, while US President Donald Trump slipped more than 200 spots, the magazine said March 20, 2017. Gates, whose wealth is estimated at $86 billion, led the list for the fourth straight year. / AFP PHOTO / EMMANUEL DUNAND