As far as I can make out - the tally could be at 1,378 cases - that dwarfs any of the previous 4 waves of H7N9. You can see that below in the crudely estimated monthly tallies.
Dwarfs by quite a lot.
Coming into this season there were about 808 human cases, so there could have been as many as 570 cases this season.
This is a very crude graph though because its unclear whether any of he number up until December were reported by the Hong Kong Centre for Health Policy in any of their recent posts. As you may know, I follow FluTracker's line list for my H7N9 data. Sadly, they recently lost the ability to list individual cases when those details mounted up too quickly and without enough clarity.
It's possible I'm up to 150 cases over in my count - but even so, 1,222 recently reported by the WHO  is still a big season.
Hopefully we'll find out when the next authority issues a total.
I've updated my other graphs on the static page (click on the Avian Influenza|H7N9 tab above or here)