This stats only show how bad the Symbian line has done in the smartphone segment the last years. I don't think anyone denied that. The earlier growth is only a movement between dumbphones to smartphones in the market, it was not a movement to nokia. Totally Nokia has (mostly) lost market share slowly since 2008 in unit sold phones if I'm remember correct. (I'm nut sure but I'm guess their last really successful premium phone was the n95 released same years as the first Iphone)
But I think the pictures stats look suspect. I think it exclude the asha smartphone lines or something, I'm pretty sure Nokia last quarter still sold more asha smartphones than lumia phones in unit sold phones.
Yes, Asha(S40) is not included because only Nokia sees Asha as smartphones while the analysts don't.
As the asha lines is the successor to many of the earlier s60 phones you get pretty meaningless stats if you exclude the asha phones.
Either you should exclude many of the earlier s60 phones or include asha.
While it's debatable whether Ashas are smartphones or not, calling S40 a successor to S60 is a bit of a stretch. UI-wise maybe, but certainly not in functionality.
Besides, sales of "Asha full touch smartphones" fell almost by half QoQ (down 46% from 9.3mln to 5.0mln) while total handset sales only fell 28%. So they are becoming less relevant inside Nokia even. The most likely cause is competition from sub-$100 Android phones.