Despite Russian President Dmitry Medvedev’s efforts to fight corruption, its level in Russia remains extremely high, with the country ranking 143rd out of 182 countries in Transparency International's 2011 Corruption Perceptions Index published on Thursday.

Russia’s ranking indicates an improvement on its 154th place in the Berlin-based anti-corruption watchdog’s 2010 list.

But despite this, the country remains the world’s most corrupt major economy, with a score of 2.4 on a scale from 0 (highly corrupt) to 10 (highly clean) and the level of graft equal to those of Uganda and Nigeria.

New Zealand (9.5) tops Transparency International's list as the least corrupt county, followed by Denmark (9.4) and Finland (9.4). The most corrupt countries are Somalia and North Korea, both having scored 1.0.

Yelena Panfilova, the head of Transparency International's Russian branch, earlier said a score below 3 describes the level of corruption in a country as extremely high. The 2011 index shows that nearly two thirds of the listed countries score below five.

Medvedev has declared a fight against corruption one of the cornerstones of his domestic policies. He has agreed to step down in favor of Prime Minister Vladimir Putin when his presidential term expires in 2012, allowing Putin to run for the presidency next March.