JOHANNESBURG — Somalia has bottomed out in an annual ranking of the perceived corruption of nations, joining Afghanistan and North Korea.

Transparency International's annual Corruption Perceptions Index, released Wednesday, shows Somalia ranked at 174 out of the 174 nations surveyed. Botswana was the highest of all African nations, coming in at 30.

The index measures the perception of corruption in the public sector.

Here's how some other African nation ranked in the survey:

-Ghana: 64;

-South Africa: 69;

-Nigeria: 139;

-Cameroon, Central African Republic and Republic of Congo: 144;

-Eritrea and Guinea-Bissau: 150;

-Guinea: 154;

-Angola: 157;

-Congo and Libya: 160;

-Equatorial Guinea and Zimbabwe: 163;

-Burundi: 165;

-Sudan: 173.