Manually associates PRAs to cities, where the mapping is incomplete or ambiguous. Also takes care of multiple PRAs being associated to a single city via CODGEO, in which case we take a simple average over all concerned PRA prices.
pra_2000()Input data are from read_terre_labourable_2000()
Writes output data to
data/statistique-agricole/petite-region-agricole/area-pop-prices-2000-labourable.csv
Writes the list of cities with multiple PRAs to
data/statistique-agricole/petite-region-agricole/area-pop-prices-2000-labourable-fixlist.csv