CREATE TABLE "ro_ro_passenger_ships" (
  "ship_name" text,
  "year" real,
  "length" text,
  "width" text,
  "passengers" real,
  "vessels" real,
  "speed" real
);

Question: What is the average speed for ships before 1974 with over 1.73 passengers?
SQL: SELECT AVG("speed") FROM "ro_ro_passenger_ships" WHERE "year"<1974 AND "passengers">1.73;

Question: How many vessels are named aqua jewel?
SQL: SELECT COUNT("vessels") FROM "ro_ro_passenger_ships" WHERE "ship_name"='aqua jewel';