Database: scholar
Question: How many papers does jamie callan publish each year ?
SQL:
SELECT DISTINCT COUNT ( t3.paperid )  ,  t3.year FROM writes AS t2 JOIN author AS t1 ON t2.authorid  =  t1.authorid JOIN paper AS t3 ON t2.paperid  =  t3.paperid WHERE t1.authorname  =  "jamie callan" GROUP BY t3.year;