user: Question: What is the sum of Points for 250cc class, ranked 13th, later than 1955?
Columns: ['Year', 'Class', 'Team', 'Points', 'Rank', 'Wins']
Types: ['real', 'text', 'text', 'real', 'text', 'real']
Sample row: [1955.0, '250cc', 'RD Special', 2.0, '13th', 0.0]
SQL:

assistant: SELECT SUM("Points") FROM "Table" WHERE "Class" = '250cc' AND "Rank" = '13th' AND "Year" > 1955.0;