The duty to be maintained on crude oils shall not. however, be such as to result in an increase of more than 59c in the difference existing on 1 January 1957 between the duties on crude oils and those on the derivatives referred lo above.
An dleacht atá le coimeád i bhfeidhm ar olaí amha, áfach, ní dleacht í a thabharfaidh go mbeidh níos mó ná 5 % de mhéadú sa difríocht a bhí ann ar an 1 Eanáir 1957 idir na dleachtanna ar olaí amha agus na dleachtanna ar na díorthaigh dá dtagraítear thuas.