Complex sentence: Only 4.4% of the population are estimated to be more than 65 years old, comprising 681,252 females and 597,628 males, whereas 61.1% of the population is between 15 and 64 years old, and 34.6% is estimated at younger than 14 years.
Split into simpler sentences: Only 4.4% of the population is estimated to be more than 65 years old, comprising 681,252 females and 597,628 males. Sixty one per cent of the population is between 15 and 64 years old, and 34.6% is younger than 14 years.