user: Question: Which Points is the lowest one that has a Year larger than 1974, and a Rank of 15th?
Columns: ['Year', 'Class', 'Team', 'Points', 'Rank', 'Wins']
Types: ['real', 'text', 'text', 'real', 'text', 'real']
Sample row: [1973.0, '250cc', 'Yamaha', 21.0, '11th', 0.0]
SQL:

assistant: SELECT MIN("Points") FROM "Table" WHERE "Year" > 1974.0 AND "Rank" = '15th';