Original sentence: According to a report by Boris Nemtsov as well as some other sources, corruption grew several times and assumed "systemic and institutionalised form", although a CPI ranking for Russia published by Transparency International has seen an average decline of only 15% in 2002-2007, falling from 2.7 to 2.3.During his first term in office, he moved to curb the political ambitions of some of the Yeltsin-era oligarchs such as former Kremlin insider Boris Berezovsky who had previously helped Putin come to power and funded his party.Following the success of his preferred successor, Dmitry Medvedev, in the 2008 presidential elections, he was then nominated by the latter to be Russia's Prime Minister and took the post on May 8, 2008.Some media reports speculated that a new group of business magnates controlling significant swathes of Russia's economy, such as Gennady Timchenko, Vladimir Yakunin, Yuriy Kovalchuk, Sergey Chemezov, with close personal ties to Putin, emerged  although Timchenko denied this.This was seen by the Kremlin as a series of anti-Russian propaganda attacks orchestrated by western opponents and exiled oligarchs.While several Yeltsin-era oligarchs such as Boris Berezovsky and Mikhail Khodorkovsky were either exiled or put in jail, the vast majority of them such as Mikhail Fridman, Viktor Vekselberg, Vladimir Potanin, Roman Abramovich,Alexander Abramov, Mikhail Prokhorov, maximized and consolidated their control over Russian natural resources and cash flows
Edited sentence: According to a report by Boris Nemtsov as well as some other sources, corruption grew several times and assumed systemic form, although a CPI ranking for Russia published by Transparency International has seen an average decline of only 15% in 2002-2007, falling from 2.7 to 2.3.Following the success of his hand-picked successor, Dmitry Medvedev, in the 2008 presidential elections, he was then nominated by the latter to be Russia's Prime Minister and took the post on May 8, 2008