commiss notic technic adapt method set refer discount rate text eea relev juli commiss decid adopt effect august method set updat refer discount rate member state inform letter date august notic publish offici journal european commun septemb method set refer rate member state basi indic rate defin monthli averag year interbank swap rate adjust premium entri stage econom monetari union januari view euro financi market commiss decid make technic adapt august refer rate ident eleven member state adopt euro countri indic rate defin averag year interbank swap rate premium basi point aspect method outlin commiss notic septemb continu appli member state adopt euro method set refer rate unchang