So you are telling me that in the last 18 months MS sold around 10M X360 out of the 21.3M Xboxs sold? not likely.If they have sold over 10 million, it won't be by much, so I think it's close enough that it doesn't really matter.
How do we know they didn't sell 15+ XB1 for example up until now? we don't have the split.