What is the quantity with more than 45 seats and MCI make?
CREATE TABLE "historical_fleet" (
  "make" text,
  "year_placed_in_service" text,
  "quantity" real,
  "number_of_seats" real,
  "wheelchair_accessible" text,
  "current_status" text
);
SELECT "quantity" FROM "historical_fleet" WHERE "number_of_seats">45 AND "make"='mci';