| Day | Rate | Set date |
|---|---|---|
| 1 May | 19.7000 | .. |
| 5 May | 19.6900 | .. |
| 6 May | 19.6400 | .. |
| 7 May | 19.5600 | .. |
| 8 May | 19.7000 | .. |
| 11 May | 19.8900 | .. |
| 12 May | 19.8600 | .. |
| 13 May | 19.9700 | .. |
| 14 May | 19.8300 | .. |
| 15 May | 19.5900 | .. |
| 18 May | 19.4600 | .. |
| 19 May | 19.1800 | .. |
| 20 May | 19.1800 | .. |
| 21 May | 19.6800 | .. |
| 22 May | 19.7200 | .. |
| 26 May | 20.6900 | .. |
| 27 May | 20.7000 | .. |
| 28 May | 20.6600 | .. |
| 29 May | 20.7900 | .. |