I had the same thought. It's obvious that all Wiis, Wii Us, and XB360s ever sold are included in that console number. Besides not being x86 (and in the case of the Wii, not even being a programmable GPU of any kind), virtually all of those Wiis and most of those 360s will have gone to the attic by now. Those are dead consoles.The table tries to call everything "installed base", which seems dubious because of the longevity issues and general fall-off in console use from 100% utilization. I do not know how the 2016 numbers can be reached unless you include the lifetime shipments of the Wii (Wii U???), Xbox 360, and the PS4+Xbox One, and how that could possibly be workable since you can bet good money that a measurable fraction of those consoles haven't been active for years or had a RROD event.
Chipworks had a die shot that had a 2012 marking on the Durango die, which given the lead time from when the pattern would have been taped out, then to fabrication, and then mass production and distribution starting ahead of the 2013 launch makes sense. The chip wouldn't be part of any installed base (can't really count dev kits) until it managed to get through all that in 2013.
A quick and dirty effort to correct the numbers would be to subtract the 2012 total from the console total; this removes most of the Wiis and 360s. This brings the total for current-generation consoles to 112.38. And to be generous, because the Wii U launched in 2012, we'll add the 3M units sold in 2012 to that total. So we're up to a 115.38M console installed base for 2016. (Alternatively, you can subtract 13.36M units of Wii U if you want to remove it entirely, since it's not x86)
AMD: 115.38 + 101.81
NV: 164.32
Intel: 144.35
Total: 525.86
Relative shares
AMD: 41.3%
NV: 31.2%
Intel: 27.5%
Which still puts AMD in the lead. But it's not nearly as impressive as 57% of the total market as AMD's PR blast likes to claim.