аҳолӣ: population, inhabitants
Every year the population of Tajikistan increases by about 100 thousand people.
Зиёда аз 75 фоизи аҳолии Тоҷикистон дар деҳот зиндагӣ мекунанд.
More than 75 percent of the inhabitants of Tajikistan live in villages.
The word аҳл is Arabic in origin. Its plural form, аҳолӣ, is quite different from the singular although some of the letters are the same. Here are some more examples of Arabic origin words with interesting plurals. Note that these words also (and more commonly) take the normal plural ending, ҳо.
тифл – атфол: child – children
ҳодиса – ҳаводис: event – events
амр – умур: command – commands