the graph is false. According to: http://www.neogaf.com/forum/showthread.php?t=922489
Sony is at 13.5 million PS4 shipped total, not sold, in October.
Everything is shipped. The graph is correct, 13.5M as of end of September for PS4, counting on x-axis is from the corresponding first launch date, not start of a year or NA launch or something else.