Go back up a level...
Drill down further...
COPA COPC COPE COPH COPI COPJ COPL COPM COPN COPO COPP COPR COPS COPT COPU COPW
Surnames shown in bold text represent around 90% of the population of Great Britain. All other names are very uncommon in the UK and we are unlikely to have any useful data on them.