Also from the past - 1926

[railtechnician]

According to the Electrical Times, the new tube extensions from Clapham to Morden and from Charing Cross to Kennington via Waterloo are expected to be in service next midsummer. It is expected that 5577 trains a day will serve the various terminals of the Hampstead and City lines together with their extensions. During each rush hour thirteen trains in each direction will run between Morden and Golders Green via the City. During the slack mid-day period Morden trains will run to Edgware via Charing Cross ; seventeen trains an hour will be the service in each direction. During rush hours twenty-six trains will run in each direction between Tooting and Euston, Golders Green and Highgate via the City, and the same number of trains per hour will run from Tooting to and from the Edgware line via Charing Cross, and Euston via the City during slack hours. From Kennington fifty-four trains an hour will be provided during busy times, serving Euston, Golders Green, and Highgate via the City and to Highgate, Colindale and Edgware via Charing Cross. The operation of these services will entail the employment of about 300 additional men as motor men, guards and station staff. 

Copied verbatim from The Engineer 01.01.1926

Note how the service level statistic has been 'bigged up' with that massive sum of 5577 trains a day!

[Nortube]

They don't exactly state things very clearly!
I'm assuming that the peak service through Tooting is 26 trains NB and 26 trains SB
Off-peak, the service through Tooting is 13 trains NB and 13 trains SB

Peak hours from Kennington seem to be the same as Tooting with two additional trains. Depending on how you look at it, that could mean either one or two trains reverse at Kennington in the peak. (do you count a reversing train as one NB and one SB?). From the destination descriptions, it would seem that trains are all over the place, a bit like the 1961 WTT. Either way, they're providing a nearly two minute service from Tooting which is quite good considering that any delay in the Tooting reversers will delay SB trains and delay NB trains from Morden. Still, it probably looks nice on paper!

Camden Town junction would be very busy in those lever pulling days, although Kennington probably wouldn't be far behind.