List each patient's ID and blood glucose (GLU) index that were within normal range for patient's whose data was first recorded in 1991.
blood glucose (GLU) index that were within normal range refers to GLU < 180; data that was first recorded in 1991 refers to year(Description) > = 1991;
SELECT DISTINCT T1.ID, T2.GLU FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID WHERE STRFTIME('%Y', T1.`First Date`) = '1991' AND T2.GLU < 180