During his first tenure as president, the Russian economy grew for eight straight years, with GDP measured by purchasing power increasing by 72%, real incomes increased by a factor of 2.5, real wages more than tripled; unemployment and poverty more than halved and the Russians' self-assessed life satisfaction rose significantly. The growth was a result of a fivefold increase in the price of oil and gas, which constitute the majority of Russian exports, recovery from the post-Communist depression and financial crises, a rise in foreign investment, and prudent economic and fiscal policies. Serving under Dmitry Medvedev from 2008 to 2012, he oversaw large-scale military reform and police reform. In 2012, Putin sought a third term as president and won with almost 64% of the vote. Falling oil prices coupled with international sanctions imposed at the beginning of 2014 after Russia's annexation of Crimea and the War in Donbas led to GDP shrinking by 3.7% in 2015, though the Russian economy rebounded in 2016 with 0.3% GDP growth, and the recession officially ended. Development under Putin has included the construction of pipelines, the restoration of the satellite navigation system GLONASS, and the building of infrastructure for international events such as the 2014 Winter Olympics in Sochi. Putin received 76% of the vote in the 2018 election and was re-elected for a six-year term ending in 2024.