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

Compare the average of artists' age by country in a bar graph, 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 NULLS LAST