Halo 5, ROTTR, Forza 6, Gears sold over 1 million as Xbone outpaces the 360

[JRPGfan]

CGI-Quality said:

JRPGfan said:
"Thanks to you, Xbox One continues to outpace Xbox 360 at the same point in time in the Xbox 360 generation, making it the best-selling console in Xbox console history."

How much was the Xbox360 at at this time?
Someguy on Neogaf says it was 17.7m so this is confirmation XB1 is over that.

It should be over that, by this point. I'm thinking it ended 2015 between 19 and 20 million.

Is that because of VGC estimates? Neogaf is saying 18-19m range.