Pretty sure I understand this too. Shipped>sold usually unless the previous month has been overshipped. My original estimation was based on this, so roughly 3.41m (sold) + 1.6m in transit, so roughly 5m shipped. Maybe that's a little optimistic though.
But you don't add this 1,6 to the last quarter quantity...You only add the adjustment of this 1,6.
So if the transit stock varies from 1,6 to 2,2 M eventually, you add only 0,6 M.
Current PB on Secret of Mana remake : 2h27 (2nd)
Strongest worldwide achievement on TGM : 1st European S13 rank
Fastest TI MASTER in Europe : rank Master V in 5min10
Current PB on Power Ranger (Game Gear) : 10min06 (World Record)
Non-geek activity : ThermalHungary
LET'S FACE THIS FACT : The Switch is the last physical video game system of the history who has a chance to beat PS2's sales.