-- Database schema
| film : Film_ID [ INT ] primary_key , Title [ TEXT ] , Studio [ TEXT ] , Director [ TEXT ] , Gross_in_dollar [ INT ] | market : Market_ID [ INT ] primary_key , Country [ TEXT ] , Number_cities [ INT ] | film_market_estimation : Estimation_ID [ INT ] primary_key , Low_Estimate [ INT ] , High_Estimate [ INT ] , Film_ID [ INT ] film_market_estimation.Film_ID = film.Film_ID , Type [ TEXT ] , Market_ID [ INT ] film_market_estimation.Market_ID = market.Market_ID , Year [ INT ] |
-- -- What is the average ticket sales gross in dollars of films?

SELECT avg(Gross_in_dollar) FROM film;