re sometimes used to distinguish between initially
identical terms (WTO: WTrO for World Trade Organization and WToO for
World Tourism Organization.)

Administrative divisions
This entry generally gives the numbers, designatory terms, and first-
order administrative divisions as approved by the US Board on
Geographic Names (BGN). Changes that have been reported but not yet
acted on by BGN are noted.

Age structure
This entry provides the distribution of the population according to
age. Information is included by sex and age group (0-14 years, 15-64
years, 65 years and over). The age structure of a population affects a
nation's key socioeconomic issues. Countries with young populations
(high percentage under age 15) need to invest more in schools, while
countries with older populations (high percentage ages 65 and over)
need to invest more in the health sector. The age structure can also be
used to help predict potential political issues. For example, the rapid
growth of a young adult population unable to find employment can lead
to unrest.

Agriculture - products
This entry is a rank ordering of major crops and products starting with
the most important.

Airports
This entry gives the total number of airports. The runway(s) may be
paved (concrete or asphalt surfaces) or unpaved (grass, dirt, sand, or
gravel surfaces), but must be usable. Not all airports have facilities
for refueling, maintenance, or air traffic control.

Airports - with paved runways
This entry gives the total number of airports with paved runways
(concrete or asphalt surfaces). For airports with more than one runway,
only the longest runway is included according to the following five
groups - (1) over 3,047 m, (2) 2,438 to 3,047 m, (3) 1,524 to 2,437 m,
(4) 914 to 1,523 m, and (5) under 914 m. Only airports with usable
runways are included in this listing. Not all airports have facilities
for refueling, maintenance, or air traffic control.

Airports - with unpaved runways
This entry gives the total number of airports with unpaved runways
(grass, dirt, sand, or gravel surfaces). For airports with more than
one runway, only the longest runway is included according to the
following five groups - (1) over 3,047 m, (2) 2,438 to 3,047 m, (3)
1,524 to 2,437 m, (4) 914 to 1,523 m, and (5) under 914 m. Only
airports with usable runways are included in this listing. Not all
airports have facilities for refueling, maintenance, or air traffic
control