-- Database schema
| Question : questiontext [ TEXT ] , questionid [ INTEGER ] primary_key | Survey : SurveyID [ INTEGER ] primary_key , Description [ TEXT ] | Answer : AnswerText [ TEXT ] , SurveyID [ INTEGER ] , UserID [ INTEGER ] , QuestionID [ INTEGER ] |
-- -- From 2016 to 2019, how many users each year were asked the question 13?

SELECT SurveyID, COUNT(UserID) FROM Answer WHERE QuestionID = 13 AND SurveyID BETWEEN 2016 AND 2019 GROUP BY SurveyID;