translate English to French: A substantial part of tier one assets (which include debt instruments only) is made up of general government securities, (i.e. assets issued by central, state and local governments and social security funds) and of Pfandbriefstyle securities issued by credit institutions and backed by residential mortgages or by public sector debt.
Le niveau le plus élevé des réserves obligatoires totales a atteint 131,7 milliards d’euros durant la période de constitution ayant pris fin le 23 février 2002 et le plus bas, 127,7 milliards durant la période de constitution ayant eu pour terme le 23 octobre.