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Drill down further...
BRATA BRATB BRATC BRATE BRATF BRATG BRATH BRATI BRATK BRATL BRATM BRATN BRATO BRATR BRATS BRATT BRATU BRATV BRATW BRATZ
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.