Gates back on top of ‘Forbes’ billionaire list

The annual list counted 1,645 men and women as billionaires, with an average wealth of $4.5bn and a collective wealth of $6.4 trillion, up $1tn from a year ago.
Gates, co-founder of the US software firm, showed his staying power at the top — the world’s richest man for 15 of the past 20 years, according to Forbes — despite spending recent years giving away large sums of money to global health and anti-poverty programmes.