4(1)In section 65(1) of the [1960 c. 44.] Finance Act 1960 for " two years " substitute " four years " , and—
(a)in paragraph (a) of the said subsection (1) for " three years " substitute " five years " , and
(b)in paragraph (b) of that subsection for " four years" substitute " six years ".
(2)Sub-paragraph (1) above shall not have effect so as to give a lesser percentage reduction than the percentage reduction (if any) which, assuming that the deceased had died on 19th March 1968, would have fallen to be made under the said subsection (1) without the amendments made by this paragraph.