TODO: case version analysis

[rkboyce]

This TODO is for Rich's team at Pitt --

There is an open question about how different case versions are and how much it matters if a specific single version is chosen during analyses. We will sample some % of FAERS reports with multiple cases (e.g., 20%) and then create a table that shows the frequency of fallout and changes across case versions (1, 2, 3, ... max) for each column of case reports.