decis execut committe octob contribut iceland norwai cost instal oper si sch execut committe regard articl convent implement schengen agreement regard articl abovement convent regard articl cooper agreement contract parti schengen agreement schengen convent republ iceland kingdom norwai decid contribut iceland norwai hereinaft refer state cooper agreement cost instal oper si contribut state cooper agreement correspond share total gross domest product contract parti state cooper agreement contribut contract parti calcul pursuant articl schengen convent method calcul contribut iceland norwai calcul mean comparison gross domest product contract parti state cooper agreement contribut contract parti member state eu calcul basi ad tax assess base pursuant sentenc articl schengen convent deduct contribut iceland norwai deadlin payment contribut nordic state fix januari vienna octob chairman schlögl