総務省の統計情報のページを見てましたら、面白いものがありました。
過去と将来の人口などのデータがありましたんで、それをいろいろ加工して作ったのが次の表です
| 西暦 | 人口(単位:千) | 老齢人口 | 老齢者割合 |
| 1930 | 64,450 | 2,941 | 4.56% |
| 1935 | 69,254 | 3,021 | 4.36% |
| 1940 | 71,933 | 3,064 | 4.26% |
| 1945 | 72,147 | 3,225 | 4.47% |
| 1950 | 84,115 | 3,454 | 4.11% |
| 1955 | 90,077 | 3,700 | 4.11% |
| 1960 | 94,302 | 4,155 | 4.41% |
| 1965 | 99,209 | 4,786 | 4.82% |
| 1970 | 104,665 | 5,398 | 5.16% |
| 1975 | 111,940 | 6,236 | 5.57% |
| 1980 | 117,060 | 7,393 | 6.32% |
| 1985 | 121,049 | 8,865 | 7.32% |
| 1990 | 123,611 | 10,647 | 8.61% |
| 1995 | 125,570 | 12,468 | 9.93% |
| 2000 | 126,926 | 14,895 | 11.74% |
| 2005 | 127,768 | 18,261 | 14.29% |
| 2010 | 128,057 | 22,005 | 17.18% |
| 2015 | 125,430 | 33,781 | 26.93% |
| 2020 | 122,735 | 35,899 | 29.25% |
| 2025 | 119,270 | 36,354 | 30.48% |
| 2030 | 115,224 | 36,670 | 31.82% |
| 2035 | 110,679 | 37,249 | 33.65% |
| 2040 | 100,443 | 38,407 | 38.24% |
| 2045 | 89,930 | 36,463 | 40.55% |
| 2055 | 79,043 | 33,028 | 41.78% |
| 2065 | 68,216 | 28,798 | 42.22% |
| 2075 | 58,983 | 24,521 | 41.57% |
| 2085 | 51,165 | 20,976 | 41.00% |
| 2095 | 44,592 | 18,105 | 40.60% |


