After the Russian-Ottoman Wars of the second half of 18th century (1768–74 and 1787–92) and acquisition of all territory of modern Southern Ukraine, number of settlements and cities with Turkic or other names in region were renamed in Greek or Russian manner. Following the World War II any trace of Crimean Tatar toponymy was predominantly removed in Crimea and Kherson Oblast. Russian is the dominant language in the region (in the schools of the Ukrainian SSR learning Ukrainian was mandatory), although not to the extent that it is in the three oblasts that comprise Eastern Ukraine. Effective in August 2012, a new law on regional languages entitles any local language spoken by at least a 10% minority be declared official within that area. Within weeks Russian was declared as a regional language in several southern and eastern oblasts and cities. Russian could then be used in these cities/oblasts' administrative office work and documents. On 23 February 2014, the Ukrainian parliament voted to repeal the law on regional languages, which would have made Ukrainian the sole state language at all levels even in Southern and Eastern Ukraine. This vote was vetoed by acting President Turchynov on March 2. Nevertheless the law was repealed by the Constitutional Court of Ukraine on 28 February 2018 when it ruled the law unconstitutional. Noticeable cultural differences in the region (compared with the rest of Ukraine, except Eastern Ukraine) are more "positive views" of the Russian language and of Joseph Stalin and more "negative views" of Ukrainian nationalism. In the 1991 Ukrainian independence referendum, a lower percentage of the total electorate voted for independence in Eastern and Southern Ukraine than in the rest of the country. In a poll conducted by Kyiv International Institute of Sociology in the first half of February 2014, 19.4% of those polled in Southern Ukraine believed "Ukraine and Russia must unite into a single state"; nationwide this percentage was 12.5. During elections voters of the Southern (and Eastern) oblasts (provinces) of Ukraine vote for the parties (Communist Party of Ukraine, Party of Regions) and the presidential candidates (Viktor Yanukovych) with a pro-Russian and status quo platform. The electorate of the CPU and the Party of Regions was very loyal to them. But following the 2014 Ukrainian Revolution the Party of Regions collapsed and the Communist Party was banned and declared illegal. According to a 2016 survey of religion in Ukraine conducted by the Razumkov Center, around 65.7% of the population of southern Ukraine declared to be believers in any religion, while 7.4% declared to be non-believers, and 3.2% declared to be atheists and agnostics. the study also found that 77.6% of the total Southern Ukraine population declared to be Christians (71.0% Eastern Orthodox, 5.1% simply Christians, 0.5% Latin Rite Catholics, 0.53% members of various Protestant churches, 0.5% members of the Ukrainian Greek Catholic Church), and 0.5% were Jewish.