Of course I do :-). The lowest impedance domestic mains supply I've ever
encountered was about 0.05 ohm (phase-neutral loop) so c. 5 kA fault
level.

Mine is certainly much lower, despite living in an urban area. I can't
remember the figure, but it is less than 2kA. Not that you are allowed to
rely on it, in case of upgrading in the supply somewhere.

Christian.