Sampling errors Males who have had sexual relationships in the last year. Variation coefficient by age group and use of a prostitute in the last year. Units: % ;Total;Yes;No; Total;1.47;6.89;1.58; From 18 to 29 years of age;2.40;10.56;2.47; From 30 to 39 years of age;2.62;10.04;2.74; From 40 to 49 years of age;2.79;13.68;2.97; Notes: Source: National Statistics Institute