In the year of 1940, the percentage of elderly people stood at 5% in Japan, while it was about 7% in Sweden and around 9% in the United States.The proportion of senior citizens in Japan dropped to 3% and remained steady to 2000. However, Sweden had an opposite trend , the percentage continuously increased from 1960 to 2040 with a slight dip in 1990 and another projected one in 2020. In the states, the percentage stayed almost steady at about 15% from the year of 1980 to 2020.