The prime weakness of the Worldscale system is the exposure of flat rates to bunker fuel prices.Flat rates are updated annually and are calculated based on bunker prices for the12-month period to September of the previous year. For 2020 flat rates that would mean the period from October 2018to September 2019.Worldscale has already announced that it will be dropping high-sulfur fuel from its calculations for 2020, stating that only compliant fuels will be considered.