user: Question: How many MotoGP winners were there when the circuit was Catalunya?
Columns: ['Round', 'Date', 'Grand Prix', 'Circuit', 'MotoGP winner', 'Moto2 winner', '125cc winner', 'Report']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [2.0, '3 April', 'bwin Spanish Grand Prix', 'Jerez', 'Jorge Lorenzo', 'Andrea Iannone', 'Nicolás Terol', 'Report']
SQL:

assistant: SELECT COUNT("MotoGP winner") FROM "Table" WHERE "Circuit" = 'Catalunya';