user: ### NOW ANSWER:
Question: What was the weekly rank by Virgin media for the title aired on May 20, 2010?
Columns: ['#', 'Title', 'Timeslot', 'Air date', 'Viewers (000s)', 'Weekly Rank Sky1', 'Weekly Rank Virgin Media']
Types: ['real', 'text', 'text', 'text', 'real', 'real', 'real']
Sample row: [85.0, '"Harbingers in the Fountain"', 'Thursday 9:00 pm', 'October 8, 2009', 954.0, 4.0, 10.0]
SQL:

assistant: SELECT MIN("Weekly Rank Virgin Media") FROM "Table" WHERE "Air date" = 'May 20, 2010';