How can I change the number of decimal places displayed in a pivot table?

How can I change the number of decimal places displayed in a pivot table?

Hi,
 
I have created a pivot table where the values are averages, calculated from the source data. The values in the source data are all to 1 decimal place, but the averages in my pivot table are showing to 5 decimal places. How can I change it to 1dp instead?
 
Thanks
Debbie