Population structure and ageing
The provided chart illustrates the percentage of people by three different age groups of a certain nation during 80 years, which started in 1960.
As can be seen, the proportion of inhabitants aged 0-14 and 15-64 decreased gradually, while this figure of upper 64 age saw a dramatic upward trend. Although the percentage of people aged 65+ was the lowest out of three at the beginning, it will become the highest level, which is the same as that of 0-to 14-year-old children.
At the beginning, the age group of 15-64 registered the highest of all three, standing at about 55%. Then this figure fluctuated slightly of approximately 4 percent each 10 years to 60 percent in 1990, before it saw a stead decline of 10 percent in 2020 and will be predicted to be continuously decreased to roughly 45 percent in 2040. Meanwhile, the percentage of citizens aged 0-14 stood at 30 percent, and then it kept observing a downward nonstop trend to 10 percent until 2040 excepting a stable pattern witnessed in the period from 1970 to 1980.
Regarding the oldest age group, albeit the rate of people aged 65 or above stayed remained between 1960 and 1970 at about 15%. This number increased to around 35% in 2020 and is guessed to continue rising in the future.