Sampling errors Persons who have had more than one sexual partner in the last year. Variation coefficient by age group and sex. Units: % ,Both sexes,Males,Females, Total,2.34,3.14,4.02, From 18 to 29 years of age,3.27,4.23,5.32, From 30 to 39 years of age,4.71,5.81,8.36, From 40 to 49 years of age,6.29,8.01,10.35, Notes: Source: National Statistics Institute