I have to register my doubt about the figure from the sofeminine site, Marina. The UCL surname profiler does not recognise the name, and its database contains, or should contain, every surname that had 100 or more bearers in in Britain in 1998. I'm sure an error has crept in. I'm unable to find any references to Sofiya as a surname in the UK, or anywhere else for that matter. The same goes for Zofiya, in the UK anyway.