I'd recommend this if you added the rate of growth per day in percent (between 30-40% worldwide additional cases per day, applying also to deaths per day).
E.g.:
2020-03-14: 0.0019%
2020-03-21: 0.02% ( = 0.0019% * (1,4 ^ 7))
2020-03-28: 0.21% ( = 0.21% * (1,4 ^ 7))
2020-04-03: 2.22% ( = 2.22% * (1,4 ^ 7))
2020-04-10: 23.43% ( = 23.43% * (1,4 ^ 7))
etc.
(Assuming a constant daily growth rate of 40%, which will probably decrease due to deaths of hosts).
E.g.:
2020-03-14: 0.0019%
2020-03-21: 0.02% ( = 0.0019% * (1,4 ^ 7))
2020-03-28: 0.21% ( = 0.21% * (1,4 ^ 7))
2020-04-03: 2.22% ( = 2.22% * (1,4 ^ 7))
2020-04-10: 23.43% ( = 23.43% * (1,4 ^ 7))
etc.
(Assuming a constant daily growth rate of 40%, which will probably decrease due to deaths of hosts).