Why is the gap between Xbox and PS4 narrowing when PS4 is winning every week?

[aken909]

November (33,000,000x2)= 66,000,000 - 68,000,000 = 2,000,000

December (35,800,000x2) = 71,600,000 - 72,300,000 = 700,000

 

If PS4 is outselling xbox the gap should always grow, thats basic math, the gap should only shrink if xbox sells more.