Are the results not standardised? If so, surely the question of whether the paper was easier/harder has already been factored? Apologies if I've misunderstood.
They are meant to be standarised but that only works properly if there is a reasonable distribution of raw scores. If large numbers of DDs score 95%+ raw scores on maths then everyone ends up around the same standardised score. What it would really mean is that the test is too easy to differentiate them. From what I have heard it was quite possible to get 100% on the maths paper. There was enough time and the general standard of the questions was not that hard.
Standardisation doesn't apply from the outer zone because only above average children are likely to take the test. And you can see that from the entry stats because last year you needed 254 in Mar, with 220 outer zone applicants only 7 to 9 should have achieved that score or better, but instead at least 18 did.
Looking back you have needed a 257 (1 more than the highest March score) score for automatic entry.