add "y/o/y growth" column to table

[ltalirz]

Thoughtful suggestion by the reviewer

The citation trend was a popular comment in the paper, adding a sort by year-over-year growth would be useful.

Currently, the table only uses citation data from the selected year.
Growth data involves data from other years, so that would require some change to the data layout.

Perhaps one should also start looking into precomputing some data - so far, everything is computed from the citation data on the fly.

[ltalirz]

#2 would also solve this, if one could display both absolute growth and relative growth numbers

[ltalirz]

in the meanwhile, #2 is fixed, but without the option of relative growth.

It could still make sense to add the y/o/y column here, as an add-on to the statistics page that only shows the top 10.