user: Question: How many locations are listed for the Big 12 Conference?
Columns: ['Conference', 'Regular Season Winner', 'Conference Player of the Year', 'Conference Tournament', 'Tournament Venue (City)', 'Tournament Winner']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Atlantic 10 Conference', 'Temple & Xavier', 'Kevin Anderson , Richmond', "2010 Atlantic 10 Men's Basketball Tournament", 'Boardwalk Hall ( Atlantic City, New Jersey )', 'Temple']
SQL:

assistant: SELECT COUNT("Tournament Venue (City)") FROM "Table" WHERE "Conference" = 'Big 12 Conference';