| Day | Rate | Set date |
|---|---|---|
| 1 May | 19.1700 | .. |
| 2 May | 18.6700 | .. |
| 3 May | 18.5700 | .. |
| 4 May | 18.9200 | .. |
| 5 May | 19.0000 | .. |
| 9 May | 18.3300 | .. |
| 10 May | 18.4400 | .. |
| 11 May | 18.3100 | .. |
| 12 May | 18.5200 | .. |
| 15 May | 18.7500 | .. |
| 16 May | 18.7700 | .. |
| 17 May | 18.3700 | .. |
| 18 May | 18.2900 | .. |
| 19 May | 18.3900 | .. |
| 22 May | 18.4800 | .. |
| 23 May | 18.3900 | .. |
| 24 May | 18.1300 | .. |
| 25 May | 18.0000 | .. |
| 26 May | 17.3600 | .. |
| 30 May | 17.6000 | .. |
| 31 May | 17.7000 | .. |