user: Question: How many different release dates are there for the audio book with a story number 7?
Columns: ['Story #', 'Target #', 'Title', 'Author', 'Reader', 'Format', 'Company', 'Release Date', 'Notes']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [52.0, '009 9', 'Doctor Who and the Cave Monsters', 'Hulke, Malcolm Malcolm Hulke', 'John, Caroline Caroline John', '4-CD', 'BBC', '2007-09-03 3 September 2007', 'Unabridged']
SQL:

assistant: SELECT COUNT("Release Date") FROM "Table" WHERE "Story #" = 7.0;