| Day | Rate | Set date |
|---|---|---|
| 1 May | 20.5000 | .. |
| 2 May | 20.0900 | .. |
| 3 May | 19.8900 | .. |
| 4 May | 20.2900 | .. |
| 5 May | 20.3300 | .. |
| 8 May | 20.2900 | .. |
| 9 May | 19.6100 | .. |
| 10 May | 19.7500 | .. |
| 11 May | 19.4100 | .. |
| 12 May | 19.5200 | .. |
| 15 May | 19.9000 | .. |
| 16 May | 20.0800 | .. |
| 17 May | 19.9600 | .. |
| 18 May | 20.0000 | .. |
| 19 May | 20.0600 | .. |
| 22 May | 19.8100 | .. |
| 23 May | 19.7700 | .. |
| 24 May | 19.4100 | .. |
| 25 May | 19.2600 | .. |
| 26 May | 18.6900 | .. |
| 30 May | 18.7800 | .. |
| 31 May | 18.8900 | .. |