The given chart illustrates the different ages of people living in Iceland from 1990 and 2020. Overall, the size of the age group between 25 and 54 is second to none over the period, with the proportion always staying above 30%; whereas the size of the two younger ages experienced an downward trend. Additionally, the number of people in the two older age groups remained mostly unchanged. 

At the first place, the 25-54 age group accounted for one-third of the total population of Iceland in 1990, before witnessing a gradual rise throughout the period and reaching nearly a half of the population in 2020. 

In stark contrast, the age group of 0-14 fell from just over 25% in 1990 to just under 20% in 2020. Similarly, that of 15-24 followed a similar downward trend, dropping from just over 20% in 1990 to approximately 8% in 2020.   

 Regarding the two older age groups, there weren’t many fluctuations, with the percentage of age group between 65 and over hovered around 13%, except a minor increase in 2010 at around 15%; whilst the size of age group between 55 and 64 only saw a mild drop from about 14% in 1990 to 10% in 2020.