CREATE TABLE exhibition_record (Exhibition_ID NUMBER, Date CLOB, Attendance NUMBER)
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)

Bar chart x axis country y axis the average of age, and display by the names in desc.
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