| Year | Revenue (£m) |
|---|---|
| 2023 | 620 |
| 2024 | 760 |
Percentage change = (new − old) ÷ old × 100. Always divide by the original (earlier) value. The correct answer is 22.6%. Traps to avoid: 20.3% comes from the "base as average" error; 10.1% comes from the "wrong base total" error; 122.6% comes from the "ratio not change" error; 18.4% comes from the "inverted base" error.