Survey on Adult Population Involvement in Learning Activities Survey on Adult Population Involvement in Learning Activities. Year 2011 Linguistic skills of persons aged 18 to 65 years old by number of languages they can use, sex and maximum educational level achieved Units: percentage of persons ;None;One;Two;Three or more; BOTH SEX; Total;47.24;34.78;13.45;4.54; Secondary education, first stage primary education and illiterate;67.52;25.64;5.33;1.51; Intermediate level studies;38.45;39.47;16.86;5.23; Higher and university studies;23.79;44.69;22.93;8.59; MALE; Total;47.19;34.83;13.34;4.64; Secondary education, first stage primary education and illiterate;65.97;26.56;5.69;1.77; Intermediate level studies;37.88;39.94;16.57;5.61; Higher and university studies;23.45;44.35;23.51;8.69; FEMALE; Total;47.29;34.71;13.56;4.44; Secondary education, first stage primary education and illiterate;69.25;24.60;4.92;1.22; Intermediate level studies;39.01;39.01;17.14;4.84; Higher and university studies;24.10;44.99;22.41;8.50; Notes: 1) The category 'Intermediate level studies' includes: Secondary education, intermediate technical-vocational education and other. Mother tongues are excluded Data referring to 12 months before the date of the survey. The symbol '.' means that data is not available, since it may be affected by sampling errors. Source: National Statistics Institute