Only most recently Vienna's distribution is being changed over from TT to TN, so there was no way to do TN-C. To make things even nicer, until the late 1970ies large parts of Vienna ran on a 127/220V grid without neutral (I assume wye connected transformers with grounded star point, but the neutral was not supplied to the customers).
So the most common way of grounding at least kitchen and bathroom outlets was until 01/01/01 running a ground wire to the nearest available water pipe, using it as a grounding electrode (or in better cases just as a grounding conductor up to the equipotential bonding in the basement). Even though such systems have to be replaced I'm pretty sure many of them are still around. I've seen one today... too bad the water mains are all PEx tubing... [Linked Image] Think that would affect the ground resistance? [Linked Image] [Linked Image] [Linked Image]
In Austria we're limited to a maximum of 165 ohms.

With new TN-C supplies the PEN has to be grounded locally and is split up at the service entrance point (Hausanschlußkasten). Approved means of grounding are flat iron 3x30mm or round copper, 30mm in diameter and 4.5m long.
Where in Germany Schuko sockets with TN-C jumpers were retrofitted in Vienna (and most parts of Austria) the old ungrounded sockets were just left in place. Today I checked out an apartment that has one single Schuko socket on 100sq. m...