CREATE TABLE "proposed_and_under_construction_skyscrap" (
  "rank" real,
  "name" text,
  "city" text,
  "metres" real,
  "floors" real
);

Question: What is the average number of metres for the Dzelzavas Street 74?
SQL: SELECT AVG("metres") FROM "proposed_and_under_construction_skyscrap" WHERE "name"='dzelzavas street 74';