National tables: studies, age and sex. Percentages Persons 18 to 49 years by sex, parents' highest level of studies parents and main source of sexual information. Units: percentages ;Total;Old parents or relatives;Siblings or friends;Partner;Professionals;Various support;Nobody; Both sexes; Total;100.00;12.43;38.96;19.49;10.25;12.25;6.61; Lower than secondary education;100.00;10.77;38.44;20.88;10.34;11.95;7.61; Secondary education;100.00;16.45;37.83;17.75;10.23;13.84;3.91; University;100.00;18.64;43.84;12.34;9.62;12.26;3.29; Males; Total;100.00;10.51;44.17;14.92;9.83;13.44;7.13; Lower than secondary education;100.00;9.40;43.77;15.68;9.97;13.10;8.07; Secondary education;100.00;12.55;41.80;14.88;9.17;16.74;4.87; University;100.00;15.15;49.32;10.25;9.70;11.87;3.72; Females; Total;100.00;14.39;33.67;24.14;10.67;11.04;6.09; Lower than secondary education;100.00;12.15;33.06;26.14;10.73;10.79;7.13; Secondary education;100.00;20.06;34.15;20.41;11.22;11.15;3.02; University;100.00;22.72;37.44;14.80;9.52;12.72;2.80; Notes: Data corresponding to cells with less than 45,000 persons must be used with caution, because they may be affected by high sample errors. Source: National Statistics Institute