user: Question: How many letters were given to the organization with a founding date of 1997-12-12? 
Columns: ['Letters', 'Organization', 'Nickname', 'Founding Date', 'Founding University', 'Type']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['ΑΙΟ', 'Alpha Iota Omicron', '"AIO"', '1998-10-16', 'University of Michigan', 'Fraternity']
SQL:

assistant: SELECT COUNT("Letters") FROM "Table" WHERE "Founding Date" = '1997-12-12';