CREATE TABLE artist (Artist_ID NUMBER, Name CLOB, Country CLOB, Year_Join NUMBER, Age NUMBER)
CREATE TABLE exhibition (Exhibition_ID NUMBER, Year NUMBER, Theme CLOB, Artist_ID NUMBER, Ticket_Price FLOAT)
CREATE TABLE exhibition_record (Exhibition_ID NUMBER, Date CLOB, Attendance NUMBER)

Show the average of artists' age by country, and I want to sort by the X from high to low.
SELECT Country, AVG(Age) FROM artist GROUP BY Country ORDER BY Country DESC
SELECT "Country", AVG("Age") FROM "artist" GROUP BY "Country" ORDER BY "Country" DESC