. "P\u00E9riode de base d'un indice, ou \u00E0 laquelle une s\u00E9rie cha\u00EEn\u00E9e fait r\u00E9f\u00E9rence" . "Base period" . "P\u00E9riode de base" . "The period of time used as the base of an index number, or to which a constant series refers." . . "S.3.9" . . . .