That certainly changes everything. That places him in the top 20% of everyone who took that test.
Actually it places him in the bottom 20%. My point was, unless you know the range from top to bottom, 18 percentile could be more than adequate. Now if the scores range from 10-100, he would likely be in the teens which is concerning. Saying that, I always question these "silly season", unnamed source, last minute, nit pick comments.