Russia’s Oil Revenues were at the level of 50-100 billion dollars per year in the 1990s (picture 1), when oil prices were moving between 20$-40$ a barrel (picture 2), and jumped to a level between 250-400 billion dollars per year in the 2000s (picture 1), when the price of oil reached 140$+ per barrel (picture 2).
It is true that the price of oil is not the only factor determining oil revenues, but it is a critical one. The rise in oil prices and the rise in revenues was one of the main reasons of Putin’s success. Putin came to power in 1999.
Diagram 1 Russia’s Oil Revenues (Forbes)
Diagram 2 Oil Prices (Macrotrends)
“Russia's Oil Revenue: Shrinking Fast”, April 2015
http://www.forbes.com/sites/markadomanis/2015/04/06/russias-oil-revenue-shrinking-fast/
“Crude Oil Price History Chart”
http://www.macrotrends.net/1369/crude-oil-price-history-chart