 Yellen was speaking with media on her trip to Africa. Yellen said the the US Treasury estimates that the G7-led price cap on Russian crude oil and refined products to limit Russias revenues could save the 17 largest net oil-importing African countries 6 billion annuallysaid two separate price caps on Russian refined petroleum products, such as diesel and fuel oil, that are due to take effect on February 5 along with a European Union ban on diesel importsone wil... 