From: Temporal trends (1977-2007) and ethnic inequity in child mortality in rural villages of southern Guinea Bissau
Age at first birth (years)
Ethnicity
n
mean
SD
range
Balanta
1657
19.3
3.6
12
40
Beafada
2777
17.9
3.1
10
37
Fula
1361
18.0
3.4
other
2055
3.0
35
Total
7850*
18.2
3.3