The line graph depicts the modifications to the demographic trend of a certain nation according to three distinct age categories from 1960 to 2040.
It is noticeable that the population from 15 to 64 years old mostly dominated the overall population in the observed period. Additionally, while the youngest specified age group (0-14) did and will experience an upward trend, the opposite pattern was and is forecasted to be applied for the others.
Regarding the prevalence of population resources, it is evident that although 15-64 years old has experienced a series of rises and falls, it has consistently accounted for a vast majority from 1960 to 2020, fluctuating from half to 60%. Subsequently, it is anticipated to continue declining and reach roughly 45% by 2040, reflecting an overall decrease of almost one-tenth over the observed timeline.
Concerning two remaining age cohorts, notably, the population from 0 to 14 and over 65 years old commenced at 30% and approximately 15%, respectively. Afterwards, the former witnessed a drop to roughly 15% in 2000, and then went on decreasing at a lesser extent, ultimately being forecasted to reach nearly 10% in 2040. Meanwhile, albeit the first 10 years saw the plateau of the over 60 age cohort, this group subsequently grew and is projected to rise gradually, converging with the 0-14 age group in 1990 (20%) and the dominative category in 2040 (45%).