First published by Money Metals here: https://www.moneymetals.com/news/2018/11/26/global-debt-gold-investment-001659

Global debt increased at the fastest rate at the beginning of 2018. In just one quarter, total global debt jumped by more than $8 trillion. That is quite surprising as total world debt rose by $22 trillion for the full year in 2017. Thus, the increase in global debt last year averaged $5.5 trillion each quarter.