- Airports: Total number of airports. Runways must be useable, but may be unpaved. May not have facilities for refuelling, maintenance, or air traffic control.
- Airports > With paved runways > Total: Total number of airports with paved runways (concrete or asphalt surfaces)
- Airports > With unpaved runways > 914 to 1,523 m: This entry is derived from Transport > Airports > With unpaved runways, which gives the total number of airports with unpaved runways (grass, dirt, sand, or gravel surfaces) by length. For airports with more than one runway, only the longest runway is included according to the following five groups - (1) over 3,047 m (over 10,000 ft), (2) 2,438 to 3,047 m (8,000 to 10,000 ft), (3) 1,524 to 2,437 m (5,000 to 8,000 ft), (4) 914 to 1,523 m (3,000 to 5,000 ft), and (5) under 914 m (under 3,000 ft). Only airports with usable runways are included in this listing. Not all airports have facilities for refueling, maintenance, or air traffic control. The type aircraft capable of operating from a runway of a given length is dependent upon a number of factors including elevation of the runway, runway gradient, average maximum daily temperature at the airport, engine types, flap settings, and take-off weight of the aircraft.
- Airports > With unpaved runways > Total: Total number of airports with useable unpaved runways (grass, dirt, sand, or gravel surfaces)
- Gross value added by transport, storage and communication: Gross Value Added by Kind of Economic Activity at current prices - US dollars.
- Gross value added by transport, storage and communication per capita: Gross Value Added by Kind of Economic Activity at current prices - US dollars. Figures expressed per capita for the same year.
- Heliports: Total number of established helicopter take-off and landing sites (which may or may not have fuel or other services).
SOURCES: CIA World Factbooks 18 December 2003 to 28 March 2011; CIA World Factbooks 2010, 2011, 2012, 2013; United Nations Statistics Division; United Nations Statistics Division. Population figures from World Bank: (1) United Nations Population Division. World Population Prospects, (2) United Nations Statistical Division. Population and Vital Statistics Report (various years), (3) Census reports and other statistical publications from national statistical offices, (4) Eurostat: Demographic Statistics, (5) Secretariat of the Pacific Community: Statistics and Demography Programme, and (6) U.S. Census Bureau: International Database.