user: Question: How many characters is by Babs Rubenstein?
Columns: ['Character', 'Australia & New Zealand (Sydney - first run, Melbourne, Auckland)', 'London', 'Toronto / Broadway', 'Brazil', 'UK Tour', 'US Tour', 'Italy (Milan, Rome, Trieste)']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Tick (Mitzi)', 'Jeremy Stanford', 'Jason Donovan', 'Will Swenson', 'Luciano Andrey', 'Jason Donovan , Noel Sullivan', 'Wade McCollum', 'Antonello Angiolillo']
SQL:

assistant: SELECT COUNT("London") FROM "Table" WHERE "US Tour" = 'Babs Rubenstein';