user: Question: What is the earliest year of disaffiliation of a CHCH-TV station, licensed in Hamilton, Ontario?
Columns: ['City of license/market', 'Station', 'Channel TV ( RF )', 'Year of affiliation', 'Year of disaffiliation']
Types: ['text', 'text', 'text', 'real', 'real']
Sample row: ['Victoria, British Columbia', 'CHEK-TV', '6 (analog only)', 2001.0, 2009.0]
SQL:

assistant: SELECT MIN("Year of disaffiliation") FROM "Table" WHERE "City of license/market" = 'Hamilton, Ontario';