user: Question: What channels have stations that were affiliated in 2002?
Columns: ['City of license/Market', 'Station', 'Channel TV ( DT )', 'Year of affiliation', 'Owned since']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Douglas, Arizona', 'KFTU-CD (repeater of KFTU-DT)', '18 (N/A)', 'N/A', 'N/A']
SQL:

assistant: SELECT "Channel TV ( DT )" FROM "Table" WHERE "Year of affiliation" = '2002';