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

Return a bar chart showing the total number of ships' nationalities, and list in desc by the total number.
SELECT Nationality, COUNT(Nationality) FROM ship GROUP BY Nationality ORDER BY COUNT(Nationality) DESC
SELECT "Nationality", COUNT("Nationality") FROM "ship" GROUP BY "Nationality" ORDER BY COUNT("Nationality") DESC