translate English to French: As this is the case more often, relatively speaking, among ethnic and immigrant communities than among the population as a whole, it is not surprising that delinquency among those groups is also above average.
Or, tel est relativement plus souvent le cas chez les communautés d'immigrés et les groupes ethniques que dans l'ensemble de la population; rien de surprenant donc que dans ces groupes la délinquance dépasse la moyenne.