English to French Bus/Financial Accounting audit

Concernant la partie "Debtors" d'un questionnaire d'audit:
Have significant debtors been circularised for confirmation of balances? If so,

What proportions of those circularised replied either agreeing the balance or "where the balance was reconciled via timing differences which did not require an ajustment to your clients'books"?
Problème de compréhension de la phrase entre guillements.... "where the balance.... which did not" est curieux; je n'en comprends pas le sens. Merci