Botswana remains the continent’s least corrupt country, improving its ranking by three positions to reach 28th place, according to the 2015 Corruption Perceptions Index (CPI) by Transparency International.

The 2015 CPI scores and ranks 167 countries based on how corrupt a country’s public sector is perceived to be.

These scores are derived from a combination of surveys and assessments of corruption and incorporate expert opinions on public sector corruption.

Poor scores indicate the prevalence of bribery, lack of punishment for corruption and public institutions that do not respond to citizens’ needs.

Overall, two-thirds of the 168 countries on the 2015 index scored below 50, on a scale from 0 (perceived to be highly corrupt) to 100 (perceived to be very clean).

José Ugaz, Chair of Transparency International, said: “The 2015 Corruption Perceptions Index clearly shows that corruption remains a blight around the world.”

“But 2015 was also a year when people again took to the streets to protest corruption. People across the globe sent a strong signal to those in power: it is time to tackle grand corruption,” he said.

In an African context, one of the highlights in the most recent report is the elevation of Rwanda, with the small East Africa nation improving its ranking by a significant 11 positions to become Africa’s second least corrupt country and achieving the 44th spot globally.

Rwanda has made substantial progress in improving its institutional environment over the past two decades, and has consequently become the second-most reformed country globally from a business perspective, while also boasting one of the continent’s most competitive business environments.

Other countries that achieved commendable rankings include Mauritius and Namibia, improving two and 10 positions respectively, to tie in 45th spot, while Ghana is considered the fifth least corrupt country on the continent, improving five positions to reach 56th globally.

The countries that saw the largest improvements in their rankings in the latest index were Mali (improving 20 positions to reach 95th) and Togo (improving 19 positions to reach 107th).

At the other end of the index, war-torn Somalia was the worst performing African country, maintaining the last position globally (167th), followed by conflict-ridden Sudan (165th) and South Sudan (163rd).

Other African countries that continue to record disappointing performances include Angola (tied with South Sudan at 163rd globally), Libya (161st), and Guinea Bissau (158th).

Countries that recorded marked deteriorations in their rankings in the latest report include Morocco (dropping eight positions to reach 88th globally), Lesotho (slipping six positions to reach 61st), Gabon (down five positions to reach 99th), and Benin (down three positions to reach 83rd).

The continent’s two largest economies did not show any improvements in their corruption perception scores in the latest index, with South Africa and Nigeria attaining global rankings of 61st and 136th, respectively.

Jacques Nel, Analyst at NKC African Economics, said overall, 40 of the 46 countries covered on the continent showed a serious corruption problem.

“Indicators for rule of law and justice scored particularly badly, while improvements were witnessed with regard to transparency in financial management. Of the African countries covered in the index, only eight countries improved their overall scores in the latest index, while scores in 20 countries deteriorated,” he said.

The report notes that the fight against terrorism has been used by many governments as an excuse to crack down on civil liberties and civil society.

This, according to the report, has been counterproductive in many instances, as entrenched corrupt networks go unchallenged, often serving as even more financial fodder for terrorism.

“Institutional environments across the continent will become increasingly important as tailwinds related to the commodity boom dissipate and economic diversification becomes a priority,” said Nel.

“Corruption perceptions play a salient role in investment decisions, and most African countries will first have to address governance concerns in order to foster environments conducive to rapid social and economic development,” he said.