1 = male
2 = female

0 = no
1 = yes

0 = no degree
1 = Secondary school or high school
2 = Apprenticeship
3 = Baccalaureate
4 = University degree
5 = PhD/Habilitation
999 = missing data

Bf_SR-Stress Median split (49); from 49 = high
0 = low
1 = high

Bf-SR_grouping_by_stresslevel
0 = strikingly low
1 = normal
2 = slightly elevated
3 = markedly elevated
4 = severely elevated