this price data covers 1999 onwards. It has an incomplete mapping to PRA_Code, which complicates the merge to city data. We first attempt to merge the majority by department and name, and then fix manually for each city and year the missing prices (not in this function).
read_petite_1999()data is from https://agreste.agriculture.gouv.fr/agreste-web/disaron/V_0003/detail/
same data in nicer format here data/statistique-agricole/petite-region-agricole/input/DIFFUSION_VVT_2020_site_DRIAAF_cle0d516d.xlsx