For life insurance contracts concluded before 29 July 1994 (existing portfolio), the scheme of operations approved by the supervisory authority up to that date continues to apply in full. Section 12(1) applies to amendments of this scheme of operations. Of the provisions of section 141, subsections (1), (2), (3), and (6) apply correspondingly, and subsection (5) applies on the understanding that the premium reserve is to be calculated in accordance with the scheme of operations in force.