Database: scholar
Question: How many papers were written on question answering in 2011 through 2016 ?
SQL:
SELECT DISTINCT COUNT ( t3.paperid ) FROM paperkeyphrase AS t2 JOIN keyphrase AS t1 ON t2.keyphraseid  =  t1.keyphraseid JOIN paper AS t3 ON t3.paperid  =  t2.paperid WHERE t1.keyphrasename  =  "question answering" AND t3.year  >=  2011;