user: Question: What is the rank of the airport with freight ( metric tonnes ) of 255121?
Columns: ['Rank', 'Airport', 'Total Passengers', '% Change 2008/2009', 'International Passengers', 'Domestic Passengers', 'Transit Passengers', 'Aircraft Movements', 'Freight ( Metric Tonnes )']
Types: ['real', 'text', 'real', 'text', 'real', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'London Heathrow', 66036957.0, '1.5%', 60652036.0, 5254605.0, 130316.0, 466393.0, 1277650.0]
SQL:

assistant: SELECT "Rank" FROM "Table" WHERE "Freight ( Metric Tonnes )" = 255121.0;