Study the data tables below which show the changing population structure of North East England.
| Age (years) | Number of people |
|---|---|
| 0-14 | 430,000 |
| 15-29 | 510,000 |
| 30-44 | 490,000 |
| 45-59 | 500,000 |
| 60-74 | 390,000 |
| 75+ | 180,000 |
| Age (years) | Number of people |
|---|---|
| 0-14 | 450,000 |
| 15-29 | 470,000 |
| 30-44 | 520,000 |
| 45-59 | 560,000 |
| 60-74 | 440,000 |
| 75+ | 210,000 |
Which age group experienced a decrease in the number of people between 2001 and 2021?