CREATE TABLE ship (Ship_ID NUMBER, Name CLOB, Type CLOB, Nationality CLOB, Tonnage NUMBER)
CREATE TABLE mission (Mission_ID NUMBER, Ship_ID NUMBER, Code CLOB, Launched_Year NUMBER, Location CLOB, Speed_knots NUMBER, Fate CLOB)

Tell me the proportion of the nationality of all ships.
SELECT Nationality, COUNT(Nationality) FROM ship GROUP BY Nationality
SELECT "Nationality", COUNT("Nationality") FROM "ship" GROUP BY "Nationality"