Post-Brexit status of EU prisoners?

Nothing too taxing for the holiday period, but looking at the most recent parliamentary prison stats document a couple of things struck me -

• We currently hold about 2,900 prisoners from EU countries - almost a thousand from Poland alone. Will they be included in a Brexit right of residence deal?
• Christians form 50% of the prison population but 60% of the general population while Muslims form 15% of the prison population but only 4% of the General population over 15. Does this prove Christians are better people than Muslims? (Athiests are only marginally over-represented in prison)

On a serious note, younger people are becoming progressively less likely to offend, which suggests the crim bulge may be just that - a moving, ageing crim bulge - and as it works its way through and the drunks, bottlers, tea leaves and  assorted ne'er-do-wells just become too old to be serious offenders our prison population will fall. So perhaps no need for panic - those born before 1976 just seem to be more criminal.