user: Question: How many wins for bikes with under 54 points, team yamaha, a 250cc bike, and before 1977?
Columns: ['Year', 'Class', 'Team', 'Points', 'Wins']
Types: ['real', 'text', 'text', 'real', 'real']
Sample row: [1969.0, '125cc', 'Villa', 5.0, 0.0]
SQL:

assistant: SELECT SUM("Wins") FROM "Table" WHERE "Points" < 54.0 AND "Team" = 'yamaha' AND "Class" = '250cc' AND "Year" < 1977.0;