Twelve African countries are ranked among the 75 least corrupt nations in the world, according to the 2012 index published Wednesday by Transparency International.

Published annually, the Corruption Perceptions Index draws upon a range of data sources to determine how corrupt countries’ public sectors are perceived to be. On a scale from 100 (highly clean) to 0 (highly corrupt), two-thirds of all countries scored below 50. This year’s survey includes 176 countries, down from 182 in 2011.

The top eight in sub-Saharan Africa (SSA) in 2012 also led the list in 2011, with approximately the same global rankings, ranging from 65 to 43. Liberia – at number 11 in sub-Sahara with a score of 41 – saw its global ranking rise 16 points – from number 91 last year to 75 in 2012.

Botswana, Cape Verde, Mauritius, Rwanda, Namibia, Ghana and Lesotho led the SSA rankings, along with South Africa, which dropped two places this year – to nine from seven. Gambia, which was ninth last year, dropped this year to 21 in SSA and 105 globally. Tunisia, which is grouped with Middle East and North Africa (MENA) countries, is tied with Liberia at 75 on the global rankings.

Nigeria and Kenya both received the low ranking of 139, compared with 143 for Nigeria and 154 for Kenya in 2011. Cameroun, the Congo Republic (Brazzaville) and the Central African Republic are ranked 144. Angola is 157, DR Congo 160 and Equatorial Guinea 163. Crowding the bottom among the most corrupt in the world are Chad (163), Sudan (173 and Somalia (174 – last).

Below are rankings (SSA/Global) and scores for all SSA countries in the index.

1/30 Botswana 65
2/39 Cape Verde 60
3/43 Mauritius 57
4/50 Rwanda 53
5/51 Seychelles 52
6/58 Namibia 48
7/64 Ghana 45
7/64 Lesotho 45
9/69 South Africa 43
10/72 Sao Tome and Principe 42
11/75 Liberia 41
12/83 Burkina Faso 38
13/88 Malawi 37
13/88 Swaziland 37
13/88 Zambia 37
16/94 Benin 36
16/94 Djibouti 36
16/94 Senegal 36
19/102 Gabon 35
19/102 Tanzania 35
21/105 Gambia 34
21/105 Mali 34
23/113 Ethiopia 33
23/113 Niger 33
25/118 Madagascar 32
26/123 Mauritania 31
126/23 Mozambique 31
26/123 Sierra Leone 31
29/128 Togo 30
30/130 Côte d´Ivoire 29
30/130 Uganda 29
32/133 Comoros 28
33/139 Kenya 27
33/139 Nigeria 27
35/144 Cameroon 26
35/144 Central African Republic 26
35/144 Congo Republic 26
38/150 Eritrea 25
38/150 Guinea-Bissau 25
40/154 Guinea 24
41/157 Angola 22
42/160 Democratic Republic of the Congo 21
43/163 Equatorial Guinea 20
43/163 Zimbabwe 20
45/165 Burundi 19
45/165 Chad 19
47/173 Sudan 13
48/174 Somalia 8