what is the lowest grid when the laps is more than 7 and the driver is rubens barrichello?
CREATE TABLE "race" (
  "driver" text,
  "constructor" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);
SELECT MIN("grid") FROM "race" WHERE "laps">7 AND "driver"='rubens barrichello';