Microsoft recent quarterly earnings numbers. 1.6 million combined 360's and Xbones shipped to retailers over the quarter.
For comparison, there were 1.7 million PS4's alone sold to customers (not just shipped) from January 4 to March 1 (2 months).
http://www.gamespot.com/articles/xbo.../1100-6426847/
Microsoft on Thursday reported earnings for the quarter ended March 31, announcing that the company shipped (i.e. sold to retailers) 1.6 million Xbox consoles, which includes Xbox 360 and Xbox One, during the period. This compares to a combined shipment tally of 2 million consoles during the same period last year.
The company attributed the downturn primarily to "lower revenue from Xbox Platform," but offset by higher revenue from Microsoft's Surface line.