Add the possibility to plot partial cumulative numbers

[marcopiani]

Hi,

cumulative charts are very useful in at least two respects:

• they allow to compare how things have played out on the long term
• they facilitate telling apart multiple series, which may overalap significantly in daily plots

E.g., compare this plot of daily numbers vs the cumulative version

One "issue" is that the present plots of cumulative numbers are only available for the whole period. Restricting the plot to a more recent period only gives the option to show still the cumulation for the whole pandemic period

On the other hand, the table tab provides useful information in terms of the change in the cumulation

I think it would be useful to have the option to visualize the comulation only in the chosen period. See here for an example (the second plot is the "zoom-in" with redefinition of the zero baseline).

I believe (perhaps wrongly) that it might be easy to implement within the grapher, as one has simply to substract the baseline. This could be done within the dropdown with the choice of "cumulative" vs "cumulative within period" or after choosing "cumulative" with a checkbox to choose "for the selected period".

I think it is important to distinguish between how countries have fared during the whole pandemic vs how they are faring now (well in the vaccine era, and in the Omicron era), and while daily numbers are useful their cumulation offers some of the advantages argued above.

Just an idea, as per category :-)

Thanks to the whole OWID team as always for your work.

All the best,

Marco