it really does not matter as long as you know that it is not exact, it is just easier to look at the numbers not rounded off. Even though I know they are not exact... They feel exact.
End of 2009 Predictions (Set, January 1st 2009)
Wii- 72 million 3rd Year Peak, better slate of releases
360- 37 million Should trend down slightly after 3rd year peak
PS3- 29 million Sales should pick up next year, 3rd year peak and price cut