Sofia (capital) is the biggest economy in the country. About 39% of Bulgaria’s GDP is produced in Sofia. Sofia also attracts about half of the total investment in the country. City offers the most diversified and active labor market with combination of high skilled workforce, foreign languages proficiency and efficient cost of labor. Education wise, Sofia offers the greatest number of schools of all types and educational levels. As for higher education establishments, 23 of all 51 accredited universities in the country are in Sofia. Apart from an educated work force, Sofia also has the best infrastructure connectivity to offer. The city is one of the main railway hubs in the country. It is interconnected with three European transport corridors and the starting point of several motorways that connect the capital with the Black Sea coast, Turkey, Greece and Serbia. Sofia also accommodates the busiest international airport in Bulgaria, with two passenger and cargo terminals. The total capacity of the cargo terminals is 20 000 tons annually, and that of the passenger terminals is 4.6 m. passengers annually.