(1)A holder of high judicial office on retirement from that office shall be entitled during his life to a pension at the annual rate provided by this section—
(a)if he retires after 15 years relevant service or after he has attained the age of 70 years, or
(b)if at the time of his retirement he is disabled by permanent infirmity from the performance of the duties of his office.
(2)The annual rate of the pension payable under this section to a person retiring from any office after 15 or more years relevant service shall be one half of his last annual salary.
(3)The annual rate of the pension payable under this section to a person retiring from any office after less than 15 years relevant service shall be—
(a)if the period of relevant service does not amount to 6 years, one quarter of his last annual salary ;
(b)if the period amounts to 6 years or more, one quarter of that salary plus 1/40th of that salary for each completed year of service exceeding 5.