also, contrary to USA, UK change certification levels due to the ever dwindling sales, so 21 is actually the highest certified album ever with 16x platinum!
so if 25 holds up good during next year, Adele might end up having the top 2 highest certified albums ever!
also a #2 all time spot aint impossible for 21, but #1 (Queen's greatest hits at 6 million) is probably too far ahead