The Great Britain Family Names Profiling website presents the findings of a project based at University College London (UCL) that is investigating the distribution of surnames in Great Britain, both current and historic.
For any surname, the profiler can show the distribution of that surname in 1881 and 1998 using a colour coded scale ranging from least to most.
The example (right) shows the distribution of the Parmiter surname.
Surnames - Profiler (UK & Ireland)
Example showing distribution of Parmiter surname in 1881 and 1998