In the year of 1920, the percentage of elderly people stood at 5% in korean , while it was about 7% in American and around 9% in the Sweden.The proportion of senior citizens in korean dropped to 2% and remained steady to 1980. 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.