The given graph illustrates the persentage of US population who were 65 years old and over from 1900 to 2000.
Overall, there was an upward trend in the proportion of ealderly people in the USA. Furthermore, the growth rate in the second half of the centery was more notable.
In 1900, precisely 2.9% of the Americans were between 65-74, being almost three times more than those at the category of 75-84 years old. The figure for both categories rose gradually over following thirty years, until they stood at 3.8% and 1.3% respectively by 1930. However, the percentage of people who were 85 or over, which accounted for only 2% of the total population, remained almost stable in the first 30 years of the period.
1940 witnessed a moderate growth in the elderly population, when citizens aged 65-74 reached to 4.8% of the total. From that year onward, the proportion of population over 65 ascend significantly, and reached a pick of 12.5% of total in 1990. It then decreased slightly and stood at just over 12% in 2000, when the proportion of population aged 65-74, 75-84, and 85 and over comprised 1.5%, 4.4%, and 6.5% of total respectively.