Original sentence: The membership is largely state school based, usually comprising around 70–75% of undergraduates - however many of these are students are drawn from elite provincial grammar schools and the leading comprehensive schools in the Home Counties, so is somewhat less balanced than the figures suggest
Edited sentence: Most of these are students are drawn from elite provincial grammar schools and the leading comprehensive schools in the Home Counties.The membership is often state school based, usually comprising around 70–75% of undergraduates.The social composition of the Fitzwilliam student body does not differ greatly from any other Cambridge college, with the proportion of working class students, as with the rest of the university, constituting no more than a negligible amount