(1) The contribution conditions for State pension (transition) are -

(a) that the claimant has entered into insurance before attaining the age of 55 years,

(b) that the claimant-

(i) has qualifying contributions in respect of at least 520 contribution weeks, or

(ii) in the case of a person who on or before 6 April 1997, is a voluntary contributor paying contributions under Chapter 4 of Part 2, has an aggregate of qualifying contributions and voluntary contributions in respect of 520 contribution weeks, of which not less than 156 are qualifying contributions, or

(iii) in any other case, has an aggregate of qualifying contributions and voluntary contributions in respect of 520 contribution weeks of which not less than 260 are qualifying contributions,

since his or her entry into insurance,

(c) that the claimant has a yearly average or in the case of a person who attains the age of 65 years on or after 6 April 1992 an alternative yearly average of not less than 48.

(1A) In the case of a person who attained the age of 65 years before 6 April 2002, subsection (1) shall be read as if the following condition were substituted for the condition in paragraph (b):