| Day | Rate | Set date |
|---|---|---|
| 1 May | 19.9100 | .. |
| 2 May | 19.6000 | .. |
| 5 May | 19.6300 | .. |
| 6 May | 19.6600 | .. |
| 7 May | 19.6200 | .. |
| 8 May | 20.3400 | .. |
| 9 May | 20.4300 | .. |
| 12 May | 21.3800 | .. |
| 13 May | 21.3700 | .. |
| 14 May | 21.3900 | .. |
| 15 May | 21.3000 | .. |
| 16 May | 22.1200 | .. |
| 19 May | 21.5900 | .. |
| 20 May | 21.1900 | .. |
| 21 May | 21.8600 | .. |
| 22 May | 21.8600 | .. |
| 23 May | 21.6300 | .. |
| 27 May | 20.7900 | .. |
| 28 May | 20.7900 | .. |
| 29 May | 20.9700 | .. |
| 30 May | 20.8800 | .. |