One of the other things that has changed is that candidates are no longer marked against each other. I forget when it stopped, but until some point, to get a certain grade, not only did you have to achieve the required mark, but you had to be in the top how-ever-many percent of candidates.
Yes, that is what they called "norm-referencing". Where the top 8% (by the looks of that graph) got grade A, then the next so-many percent a "B" and so on.
I think it was better because it prevented the whole "grade inflation" problem. If one year the exam was easier or harder for a given subject, you would still get the same proportion of As, Bs etc.
A criticism of this method was that "if you were unlucky to be in a year group of above-average ability, you could do very well and still only get a B".
But in a year group of thousands sitting a given A Level, the statistical probability of them suddenly being much "brighter" in one year is very, very small indeed.
Giles..