domestic airport and also the only airport in the sparsely populated eastern half of the country. Tajikistan has one major airline (Somon Air) and is also serviced by over a dozen foreign airlines. Roads The total length of roads in the country is 27,800 kilometres. Automobiles account for more than 90% of the total volume of passenger transportation and more than 80% of domestic freight transportation. Opel passenger cars are most popular. In 2004 the Tajik–Afghan Friendship Bridge between Afghanistan and Tajikistan was built, improving the country's access to South Asia. The bridge was built by the United States. many highway and tunnel construction projects are underway or have recently been completed. Major projects include rehabilitation of the Dushanbe – Chanak (Uzbek border), Dushanbe – Kulma (Chinese border), and Kurgan-Tube – Nizhny Pyanj (Afghan border) highways, and construction of tunnels under the mountain passes of Anzob, Shakhristan, Shar-Shar and Chormaghzak. These were supported by international donor countries. Demographics In 2021, Tajikistan was estimated to have a population of 9,749,625 as per the World Bank data. The Tajiks who speak Tajik (a dialect of Persian) are the main ethnic group, although there are sizeable minorities of Uzbeks and Russians, whose numbers are declining due to emigration. The Pamiris of Badakhshan, a small population of Yaghnobi people, and a sizeable minority of Ismailis are all considered to belong to the larger group of Tajiks. All citizens of Tajikistan are called Tajikistanis. In 1989, ethnic Russians in Tajikistan made up 7.6% of the population; by 1998 the proportion had reduced to approximately 0.5% following the Tajikistani Civil War which had displaced the majority of ethnic Russians. Following the end of the war, Russian emigration continued. The ethnic German population of Tajikistan has also declined due to emigration: having topped at 38,853 in 1979, it has almost vanished since the collapse of the Soviet Union. The Tajiks are the principal ethnic group in most of Tajikistan, as well as in northern and western Afghanistan, and there are more Tajiks in Afghanistan than in Tajikistan. Tajiks are a substantial minority in Uzbekistan. More than 3 million Tajik citizens were officially registered in Russia in 2021. Languages The two official languages of Tajikistan are Tajik as the state language and Russian as the interethnic language, as understood in Article 2 of the Constitution: "The state language of Tajikistan shall be Tajik. Russian shall be the language