CREATE TABLE table_68925 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" FLOAT)

What is the sum of points in 1991, for footwork a11c chassis?
SELECT SUM("Points") FROM table_68925 WHERE "Year" = '1991' AND "Chassis" = 'footwork a11c'
SELECT SUM("Points") FROM "table_68925" WHERE "Chassis" = 'footwork a11c' AND "Year" = '1991'