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)
CREATE TABLE artist (Artist_ID INT, Name TEXT, Country TEXT, Year_Join INT, Age INT)

Stacked bar of year and the number of year colored by Theme
SELECT Year, COUNT(Year) FROM exhibition GROUP BY Theme
SELECT "Year", COUNT("Year") FROM "exhibition" GROUP BY "Theme"