###HUMAN: what are the top four most common lab tests until 4 years ago?, ###ASSISTANT: SELECT t1.labname FROM (SELECT lab.labname, DENSE_RANK() OVER (ORDER BY COUNT(*) DESC) AS c1 FROM lab WHERE DATETIME(lab.labresulttime) <= DATETIME(CURRENT_TIME(), '-4 year') GROUP BY lab.labname) AS t1 WHERE t1.c1 <= 4