How many users answered "Yes" to the question "Have you had a mental health disorder in the past?" in 3 consecutive years starting from 2016?
question refers to questiontext; answered 'Yes' to question refers to AnswerText = 'Yes'; 3 consecutive years starting from 2016 refers to SurveyID = 2016 and SurveyID = 2017 and SurveyID = 2018
SELECT COUNT(T2.UserID) FROM Question AS T1 INNER JOIN Answer AS T2 ON T1.questionid = T2.QuestionID WHERE T2.SurveyID IN (2016, 2017, 2018) AND T1.questiontext LIKE 'Have you had a mental health disorder in the past?' AND T2.AnswerText = 'Yes'
CREATE TABLE Question
(
    questiontext TEXT,
    questionid   INTEGER
        constraint Question_pk
            primary key
);
CREATE TABLE Survey
(
    SurveyID    INTEGER
        constraint Survey_pk
            primary key,
    Description TEXT
);
CREATE TABLE IF NOT EXISTS "Answer"
(
    AnswerText TEXT,
    SurveyID   INTEGER
        constraint Answer_Survey_SurveyID_fk
            references Survey,
    UserID     INTEGER,
    QuestionID INTEGER
        constraint Answer_Question_questionid_fk
            references Question,
    constraint Answer_pk
        primary key (UserID, QuestionID)
);
