Thanks for the reference, at least you cared to search and show it!
10% of 25,000 for that particular exam does sound a lot, and that's probably why it made national news in the first place. Does it mean 10% of all Chinese students (in China) cheat? Is it a proof that "Cheating among Chinese students is pandemic."? Definitely Not. I can find way more examples where 0% of Chinese students cheat in national level exams (actually, I probably can't, because "nobody cheated in the exam" won't make the news). Does that mean "Chinese students never cheat."? Of course not either. I'm not trying to be the PC police here, but I'm just baffled that a sweeping claim like that got used as the basis of OP's thesis and everybody seems to be agreeing with it. I thought HN's audience could do better than that...
Yeah, this is why I didn't bother constructing a more robust argument showing the clear trend. Consider that you may be unwilling to entertain the possibility that this phenomenon actually exists.
What "trend" are you referring to? "Cheating among Chinese students is pandemic." is the trend? So it used to be not "pandemic" but has become more and more so recently? That would actually be very interesting to read if not merely backed up by some hand waving stats or anecdotal evidences.
Note that this particular exam was taken by 25,000 people, so that's almost ten percent.