LONDON (Reuters) - How much damage has the coronavirus and the oil price collapse inflicted on global financial markets this year? Put simply, it has probably been the most destructive sell-off since the Great Depression. The numbers have been staggering. $15 trillion has been wiped of world stock markets , oil has slumped 60% as Saudi Arabia and Russia have started a price war and emerging markets like Brazil, Mexico and South Africa have seen their currencies plummet more than 20%.Volatility..