CREATE TABLE "classification" (
  "driver" text,
  "constructor" text,
  "laps" real,
  "time_retired" text,
  "grid" real
);

Question: When the laps are over 53, what's the average grid?
SQL: SELECT AVG("grid") FROM "classification" WHERE "laps">53;

Question: What's the average laps driven by david coulthard?
SQL: SELECT AVG("laps") FROM "classification" WHERE "driver"='david coulthard';