Author

Country

%

Picaud

Gabon, 1990

0.97

Chibani

Tunisia, 1996

2.6

Wasef

Netherlands, 2000

3.49

Bais

Belgium, 2001

3.2

Neuhaus

Germany, 2001

7.16

Myles

EUA, 2003

13.6

Aisien

Nigeria, 2004

7.5

Shi wuwen

Canada, 2004

10.5

Our study

DRC, 2017

6