Running a little off-topic, there is evidence that a Cambridge maths exam series 150 years ago had a pass mark of about one and a half percent, and the top scorer achieved about 45 percent.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mathematical_Tripos" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mathematical_Tripos</a>