United Nations reports in 1971 credited Bulgaria with the fastest developing shipbuilding industry in the world. The pronouncement is less meaningful than it might appear, however, because the industry started from very little. Moreover, a major portion of the products are for export, and much of the industry's local impact is as a production, rather than as a transportation, enterprise. Nonetheless, the country's capability for sea shipment increased by more than five times during the 1960s. There are no large passenger vessels in the fleet, but several hydrofoils, some having capacities to carry more than 100 passengers, operate between the Danube River ports. By 1972 the merchant marine consisted of more than 100 ships, having a total of nearly 1 million deadweight tons. It has increased at an average rate of about 6 percent a year between 1967 and 1971, the rates of increase accelerating in the latter part of the period. Airways Civil aviation was carried on by Bulgarian Civil Air Transport before 1970, when that entity was reorganized as Balkan-Bulgarian Airlines (BALKAN). Its airplanes, all of Soviet manufacture, are identified by BALKAN inset within a five-pointed star that is elongated to give the impression of flight. BALKAN operates under the Ministry of Transport. Sofia is the center of all the air operations. International routes stop at the capitals of the six other Warsaw Pact countries and at sixteen other cities in Europe, North Africa, and the Middle East. The 1973 scheduled flights also connected Sofia with eleven other cities within Bulgaria, most of them on a daily basis. Percentages of total cargo and passenger traffic carried by air are insignificant, and the rates of increase in the utilization of air transportation have been erratic. Air cargo shipments, for example, increased by a factor of seven between 1960 and 1967 but increased little the following year and decreased for the remainder of the decade. CHAPTER 4 SOCIAL SYSTEM