children born per woman, which is below the replacement rate of 2.1, and is one of the world's lowest fertility rates. Subsequently, the nation has one of the world's oldest populations, with a median age of 40.3 years. In 2009, it recorded annual population growth for the first time in fifteen years; and since the 2010s, Russia has seen increased population growth due to declining death rates, increased birth rates and increased immigration. However, since 2020, due to excessive deaths from the COVID-19 pandemic, Russia's population has undergone its largest peacetime decline in history. Following the Russian invasion of Ukraine in 2022, the demographic crisis in the country has deepened, as the country has faced a renewed brain drain and human capital flight caused by Western mass-sanctions and boycotts. Russia is a multinational state with many subnational entities associated with different minorities. There are over 193 ethnic groups nationwide. In the 2010 census, roughly 81% of the population were ethnic Russians, and the remaining 19% of the population were ethnic minorities; while over four-fifths of Russia's population was of European descent—of which the vast majority were Slavs, with a substantial minority of Finnic and Germanic peoples. According to the United Nations, Russia's immigrant population is the world's third-largest, numbering over 11.6 million; most of which are from post-Soviet states, mainly Ukrainians. Language Russian is the official and the predominantly spoken language in Russia. It is the most spoken native language in Europe, the most geographically widespread language of Eurasia, as well as the world's most widely spoken Slavic language. Russian is one of two official languages aboard the International Space Station, as well as one of the six official languages of the United Nations. Russia is a multilingual nation; approximately 100–150 minority languages are spoken across the country. According to the Russian Census of 2010, 137.5 million across the country spoke Russian, 4.3 million spoke Tatar, and 1.1 million spoke Ukrainian. The constitution gives the country's individual republics the right to establish their own state languages in addition to Russian, as well as guarantee its citizens the right to preserve their native language and to create conditions for its study and development. However, various experts have claimed Russia's linguistic diversity is rapidly declining due to many languages becoming endangered. Religion Russia is a secular state by constitution, and its largest religion is Eastern Orthodox Christianity, chiefly represented by the Russian