A supreme or district court judge or that person‘s beneficiary who, on December 31, 2007, is receiving retirement benefits under subdivision b of subsection 4 of section 54-52-17, is entitled to receive an increase in benefits equal to two percent of the individual‘s present benefits with the increase payable beginning January 1, 2008. A supreme or district court judge or that person’s beneficiary who, on December 31, 2008, is receiving retirement benefits under subdivision b of subsection 4 of section 54-52-17, is entitled to receive an increase in benefits equal to two percent of the individual’s present benefits with the increase payable beginning January 1, 2009. The increases allowed by this section may only be given if the public employees retirement board determines there is actuarial margin sufficient to pay the increases.