Table 1 Characteristics of the sample by gender and place of birth

Total SELFY sample size

3874

3466

171

234

Median age at interview

20.7

20.5

21.1

21.2

Interquartile range (p75-p25)

1.5

1.3

1.8

2.2

Median age at first sex^a

17.9

18.0

17.8

18.8

Interquartile range (p75-p25)

3.6

4.0

3.4

4.5

% that had first sexual intercourse

79.6

76.8

84.3

77.5

Among which:

 % that had extra-couple sexual intercourse

23.6

13.3

33.5

18.7

 % that had occasional sexual intercourse

52.8

28.8

69.5

23.2

 % that had numerous sexual partners^b

43.6

34.8

50.1

36.7