A pioneer study randomly assigned pregnant women to either a daily multivitamin supplement (including folic acid) or a placebo. In the 2104 pregnancies in the women taking the vitamin regimen, there were 28 cases of congenital malformation. In the 2052 pregnancies in the women taking the placebo, 47 cases of congenital malformation were recorded. What is the relative risk reduction, RRR, in congenital malformation when taking a multivitamin supplement compared with taking a placebo