### Database Schema:
CREATE TABLE Question (
	questiontext	TEXT	NULL,
	questionid	INTEGER	NULL	PRIMARY KEY
);

CREATE TABLE Answer (
	AnswerText	TEXT	NULL,
	SurveyID	INTEGER	NULL,
	UserID	INTEGER	NULL	PRIMARY KEY,
	QuestionID	INTEGER	NULL	PRIMARY KEY,
	foreign key (QuestionID) references Question (questionid),
	foreign key (SurveyID) references Survey (SurveyID)
);

CREATE TABLE Survey (
	SurveyID	INTEGER	NULL	PRIMARY KEY,
	Description	TEXT	NULL
);

### User's Query:
How many users, between the age 27 to 35, were surveyed in 2018?

### Extra Knowledge:
Age 27 to 35 refer to AnswerText 27 BETWEEN 35 where questionid = 1; 2018 refer to SurveyID


SELECT T1.UserID FROM Answer AS T1 INNER JOIN Question AS T2 ON T1.QuestionID = T2.questionid WHERE T1.SurveyID = 2018 AND T2.questionid = 1 AND T1.AnswerText BETWEEN '27' AND '35'