source： Japan Bureau of statistics, 1995 Population census of Japan
Also, somewhat different aspect of pattern of discrepancy in the degree of population aging between 47 prefectures can be observed using the elderly-child ratio, or the ratio of the elderly population aged 65 and over against 100 children aged less than 15. In 1995 when the ratio showed 91.2 for the nation, 22 prefectures, including Tokyo, among 47 prefectures recorded higher than 100 in the elderly-child ratio. As no prefecture indicated 100 or higher in the ratio in 1990, the degree of population aging was intensified drastically and in wider spatial range during this five year period. Among 22 prefectures with higher than 100 in the ratio as of 1995, Kochi prefecture showed the highest (133.5). Following after Kochi, the prefectures of Shimane, Akita, Yamaguchi, Yamagata, Tokushima, Toyama, Nagano and Kagawa recorded higher than 115 . Above all, it should be noted that Tokyo metropolitan prefecture presented 102 in the ratio (Table 1).
A sharp contrast in the age structures of population between metropolitan or urban prefecture and rural prefecture, observed in the population pyramids as of 1995 for Saitama prefecture with the lowest percentage for the elderly and for Shimane prefecture with the highest percentage, may depict in detail the difference in the degree of population aging (Figures 3 and 4).
