Note: one of the problems here is is how, or whether, to distinguish between West End, fringe and "off-West End" venues. Well, that one's simple: no distinction whatever is made here.
Rather knottier is how one defines "London".
Is it the area covered by the Greater London Authority? The area
with London postcodes? The area with an 020 telephone dialling code?
The area within the M25? You pays your money and you takes your choice.
And since I'm paying my money for this site, my choice is postcodes.
Thus, for example, venues in Brentford, Croydon and Richmond, all of which
have 020 phone numbers, are in the regional list rather than this one.
(Also, it evens out the numbers of entries a bit between the two tables...)