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

Compare the average of artists' age by country in a bar graph, and could you show Country from low to high order?
SELECT Country, AVG(Age) FROM artist GROUP BY Country ORDER BY Country
SELECT "Country", AVG("Age") FROM "artist" GROUP BY "Country" ORDER BY "Country" NULLS FIRST