Hi Hopping,
I guess, for your calculations you've used number of PERs received by 2174 applicants by 24th of June.
It's one possible way to calculate it, but there are other ways. I'm not so sure we should count PERs in this case. CIC stops charging applicants as soon as cap is reached, so it's possible that we should use number of charged applications instead.
Specifically, number of 2174 applications charged by 24th of June in the spreadsheet is 35. Official CIC number is 106, which means it's 33% - and it's really close to 31% from the previous year.
There's also another question - what if applications are counted towards caps somewhere in between a fee charge and PER?
For now, based on my observations, I didn't yet find a definitive answer on these questions, so it makes sense not to make any assumptions regarding this unless we know the answer.
Anyway, I trust percents obtained from FSW 2013 statistics more, as they include more applications, and they were calculated after caps were reached, which means time factor is eliminated from calculations and they're not affected by the questions above.
Update:
I've made some more research on FSW 2013 cap behavior and here are the results (part of the credit here goes to FSW13 spreadsheet admins, who had some of these stats already).
As you can see, CIC Reported Cap Full date is really close to last spreadsheet charge date. - Not to last PER, which is so far that using it would cause a really significant error in calculations.