| Age (years) | Number of people |
|---|---|
| 0-19 | 750,000 |
| 20-39 | 820,000 |
| 40-59 | 710,000 |
| 60-79 | 510,000 |
| 80+ | 110,000 |
| Age (years) | Number of people |
|---|---|
| 0-19 | 680,000 |
| 20-39 | 780,000 |
| 40-59 | 830,000 |
| 60-79 | 670,000 |
| 80+ | 180,000 |
Suggest reasons for the changes in the population structure of Wales between 1991 and 2021.