Database: imdb
Question: What is the number of movies that " Brad Pitt " acts in per year ?
SQL:
SELECT COUNT ( DISTINCT t2.title  )  ,  t2.release_year FROM CAST AS t3 JOIN actor AS t1 ON t3.aid  =  t1.aid JOIN movie AS t2 ON t2.mid  =  t3.msid WHERE t1.name  =  "Brad Pitt" GROUP BY t2.release_year;