The infection mortality rate ( IFR ) incorporates a further adjustment to allow for undiagnosed and/or asymptomatic infections ; as at 22 March 2020 it has been estimated at 0.20 % . `` Global Covid-19 Case Fatality Rates '' The Centre for Evidence-Based Medicine , Oxford University , retrieved 25 March 2020Over time , estimates for the CFR in China decreased markedly from 17.3 % ( for those with symptom onset 1–10 January 2020 ) to 0.7 % ( for those with symptom onset after 1 February 2020 ) as the quality of healthcare improved.
As the quality of healthcare improved , estimates for the CFR in China decreased from 17.3 % to 0.7 % during the 2019–20 coronavirus pandemic .