Q&A for professional and enthusiast programmers
SELECT count(*) FROM Posts P2 WHERE P2.OwnerUserId IN (SELECT owneruserid FROM posts AS P WHERE P.creationdate BETWEEN '2013-01-01' AND '2014-12-31' AND P.posttypeid = 1 GROUP BY owneruserid HAVING count(*) >= 20) AND P2.PostTypeId = 1;