Table 2. Future Trends in Population Structure: 1995-2090（percent)
Source: Institute of Population Problems, Ministry of Health and Welfare, Population Projections for Japan: 1991-2090, Tokyo, 1992.
the well-known three major age categories-under 15, 15-64 and 65 + (See also Figure 5). Columns (5) to (7) show age-dependency ratios -total dependency (See also Figure 6), child-dependency and old-age dependency. The last column indicates a relatively new concept, that is, the ratio of the elderly to chidren.
If the degree of ageing is expressed by the percentage of the total population which is 65 years and over, the Japanese age structure at present is hardly very "aged", since the percentage is approximately 13 - not particularly high in comparison with such countries as Switzerland, Sweden and the Federal Republic of Germany (1,efore the unification) where the corresponding proportions exceed 15 percent. However, according to the medium variant of the above-mentioned provisional population projections prepared by the Institute of Population Problems in 1992, the future pace
