@ Bowden,
I suspect statistics are of reduced value particularly in Rural areas.
B4RN don't attempt to compete with BT in the larger conurbations when D side distances are ofter quite short.
It's an entirely different story in sparser more rural locations where BT are virtually ignored by B4RN as their price / performance curve renders them uncompetitive.
Furthermore the rural communities have suffered for so long which encourages their community spirit to "just Do It" themselves.
As a shareholder there won't be many who would opt for any service other than B4RNs.
Network topology doesn't help BT either as many smaller exchanges had EO lines but are now equipped with cabinets close-by the exchanges such as in Silverdale and Ingleton leaving a significant number of lines far too long for VDSL.
Another example is the village of Cockerham with a PCP and FTTC fed from the Forton exchange but a large number of lines within a few hundred of metres of the Forton PCP are EO lines all the way from the Galgate exchange.
That said the whole of the B4RN area now equating to the size of the M25 ring but only has a few thousand long-distance properties.
Kind regards,
Walter