You can get the Fishing mortality by year (meanf) and what should be a sustainable fishing mortality (FMSY). Then the ration between both values is a proxy of how far we are from a sustainable fishery.

Year wg - Year of last working group
fishstock - the Ices code fro the stock
year - the time serie year value
f_etoile2 - ratio of meanf / FMSY
overfished - 1 if f_etoile2>1 then 1 else 0
maxyear - last year of the time serie
fmsy - Fishing mortality for a maximum sustainable yield
meanf - Annual Fishing mortality.