The given bar chart illustrates the proportions of the US population aged 65 and above from 1900 to 2000.
Overall, there was a substantial growth in the three age categories of the total US population over each decade, with the highest percentage observed in the 65-74 age group.
Initially, the cohort aged 65-74 constituted 2.9 percent of the population in 1900, which gradually increased to 3.3 percent by 1920. The percentage then saw a slight rise to 3.8 percent in 1930, climbing significantly to 5.6 percent by 1950. Subsequently, it experienced a significant remained stable at 3.8 percent in 1960 and 1970, before reaching a peak of 7.3 percent in 1990.
Furthermore, the percentage of the group aged 75-84 was higher than those over 85. Starting at 1 percent in 1900, the 75-84 age group surpassed the 85+ age group which began at 0.2 percent. Particularly, the US aged over 85 maintained the same level at 0.2 percent during 30 years (1900-1930) at which point the figure rose dramatically to 1.5 percent in 2000. On the other hand, the total population aged 75-84 reached 4.4 percent in the last year (2000).