CREATE TABLE artist (artist_id DECIMAL, name TEXT, country TEXT, year_join DECIMAL, age DECIMAL)
CREATE TABLE exhibition_record (exhibition_id DECIMAL, date TEXT, attendance DECIMAL)
CREATE TABLE exhibition (exhibition_id DECIMAL, year DECIMAL, theme TEXT, artist_id DECIMAL, ticket_price DECIMAL)

What are the theme and year for all exhibitions that have a ticket price under 15?
SELECT theme, year FROM exhibition WHERE ticket_price < 15
SELECT "theme", "year" FROM "exhibition" WHERE "ticket_price" < 15