The table shows the exchange rate between the pound and the Swiss franc.
| Month | Swiss francs per £1 |
|---|---|
| March | 1.10 |
| April | 1.13 |
| May | 1.17 |
| June | 1.15 |
| July | 1.20 |
| August | 1.23 |
Describe the movement in the value of the pound against the Swiss franc from March to August.