user: Question: How many networks run on virtual channel 23.4?
Columns: ['Callsign', 'City of license', 'Virtual channel', 'Digital channel', 'Network']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['WKYC', 'Cleveland', '3.1', '17.1', 'NBC']
SQL:

assistant: SELECT COUNT("Network") FROM "Table" WHERE "Virtual channel" = '23.4';