The given line graph reveals the information of population elderly people who have aged 65 and more than that, over 100 years, from 1940 to 2014, located in USA, Sweden and Japan. It can obviously be seen that the total of retire-aged man in three countries witnesses upward trend in which Japan will have the highest number of them in 2040.
Based on the data, in the first period, USA overtook the highest proportion of old people, standing at less than one in ten, followed by Sweden and Japan. Having similar pattern to USA from 1960 to 1980, the number of long-lived people in Sweden increased steeply to almost 15% while those in Japan remained steady at around 4%. There was a sudden decline in the old population in either USA or Sweden before the point rose significantly in Sweden and leveled off in USA. Surprisingly, despite of some fluctuations, it will be predicted that old man and woman in USA, Sweden and Japan will jump dramatically to approximately 23%, a quarter and more than 25%, respectively in the year of 2040.