105. Limitation on period for which previous offences taken into account
Where ¾
(a) a person is convicted of an offence (in this section referred to as }the present offence~) against this Act; and
(b) the penalty or penalties which may or shall be imposed for the present offence vary according to whether the person has been convicted previously of an offence against this Act or the repealed Act,
any such previous offence the conviction for which was recorded more than 20 years before the commission of the present offence shall not be taken into account for the purposes of determining the penalty or penalties to be imposed for the present offence.