user: Question: When in the 1st league position, how many people watch as they faced West Ham United?
Columns: ['Date', 'Opponents', 'Result F–A', 'Attendance', 'League position']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['19 August 2001', 'Fulham', '3–2', 67534.0, '4th']
SQL:

assistant: SELECT "Attendance" FROM "Table" WHERE "League position" = '1st' AND "Opponents" = 'West Ham United';