According to accurate data, as of September 2012, there were 591 taxed cerberas and a further 218 on SORN. This data doesn't include overseas cars. In comparison, there are only 118 vauxhall viva 1300's left surviving.
OP, if the information you've got is from that How Many Left website, I wouldn't take it as 100% gospel as it tries to tell me that one of my cars doesn't even exist!