It really depends on the standard and the average of the boys in the year. 2008 is the easiest (80 will be a 'pass mark'), 2011 next (80 being a reasonable mark) then 2009. The one I did was probably the longest and toughest of the lot, I got in with a 75% mark, so that means something
How did you find out your score? I didn't think that the school answer such queries. My son took it in 2010 and when he came out and said that he couldn't do 20% of the maths we thought that was it. But he still got a place. We assumed that he got full marks for the 80% that he did attempt. It would be interesting to find out what he did score.