Based on the data below, explain the likely relationship between real disposable income and subjective happiness.
| Year | Real Disposable Income (£) | Nominal Disposable Income (£) |
|---|---|---|
| 2012 | 32,000 | 26,500 |
| 2015 | 31,500 | 29,000 |
| 2018 | 32,000 | 32,000 |
| 2021 | 32,500 | 35,500 |
| 2024 | 32,000 | 39,000 |
