I kind of find that hard to believe but maybe there were government/enterprise purchases boosting it or something? As far as I'm concerned Blackberry died with the Blackberry Storm 2 in 2009, which was a huge piece of junk.
I used to go back and forth to Shenzhen all the time trading refurbs and by 2010 I straight up would not buy anything other than Android devices because 1) iPhone was actually more expensive in mainland China due to it being a grey market item back then and 2) demand for everything else fell off a cliff.