34. In calculating the claimant's income the appropriate authority may disregard any legislative change—
(a)in the basic or other rates of income tax;
(b)in the amount of any personal tax relief;
(c)in the rates of social security contributions payable under the Act or in the lower earnings limit or upper earnings limit for Class 1 contributions under that Act, the lower or upper limits applicable to Class 4 contributions under that Act or the amount specified in section 11(4) of the Act (small earnings exception in relation to Class 2 contributions);
(d)in the amount of tax payable as a result of an increase in the weekly rate of Category A, B, C or D retirement pension or any addition thereto or any graduated pension payable under the Act; and
(e)in the maximum rate of child tax credit or working tax credit,
for a period not exceeding 30 benefit weeks beginning with the benefit week immediately following the date from which the change is effective.