(a) Effective July 1, 1973, the benefits of persons eligible for survivor benefits pursuant to former Section 14186 as it read on June 30, 1972, shall be increased as follows: (1) Those eligible for ninety dollars ($90) per month shall be increased to one hundred five dollars ($105) per month. (2) Those eligible for one hundred eighty dollars ($180) per month shall be increased to two hundred ten dollars ($210) per month. (3) Those eligible for two hundred fifty dollars ($250) per month shall be increased to two hundred ninety-five dollars ($295) per month. (b) These benefits shall be subject to the provisions of Sections 22140 and 24403 with the first annual improvement to occur on September 1, 1974, and annually thereafter.