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CYA CYB CYC CYD CYE CYF CYG CYH CYK CYL CYM CYN CYO CYP CYR CYS CYT CYW CYZ
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.