Rostov Oblast is a federal subject of Russia (an oblast), located in the Southern Federal District. The oblast has an area of 100800km2 and a population of 4,277,976 (2010 Census), making it the sixth most populous federal subject in Russia. Its administrative center is the city of Rostov-on-Don, which also became the administrative center of the Southern Federal District in 2002.GeographyRostov Oblast borders Ukraine and also Volgograd and Voronezh Oblasts in the north, Krasnodar and Stavropol Krais in the south, and the Republic of Kalmykia in the east.It is within the Russian Southern Federal District.Rivers and lakesThe Don River, one of Europe's largest rivers, flows through the oblast for part of its course. Lakes cover only 0.4% of the oblast's area.DemographicsPopulation:Vital statistics for 2012Births: 49 715 Deaths: 59 376 Total fertility rate:2009 - 1.38 | 2010 - 1.38 | 2011 - 1.39 | 2012 - 1.51 | 2013 - 1.52 | 2014 - 1.61 | 2015 - 1.63 | 2016 - 1.60