I think you just want the weekly sales which are already accessible.
http://vgchartz.com/aweekly.php
the hardware is at the bottom of the software. Also, for prediction league purposes you are better off looking at "hardware by date" under chartz and looking at like the last 8 weeks, then looking at the last year. (however, you could just use the weekly and look at the last year however I like to see the trends from the last year)
Also, if you put your mouse of the "America" in the main bar, we also have monthly and yearly sales. However, I don't think we count monthly the same as NPD. i'm not sure when we cut off the month, and which weeks are in and which are out as I don't really use that page.
@RPG
the reason GAF hates VGChartz has nothing to do with accuracy, and more to do with a falling out with Brett. He was going to do this for GAF, but they didn't want to as they only believed in NPD. They got mad when he started his own website, and now they hate it. The hate is bred from the admins and mods and they have brainwashed the forum members.
As for accuracy, you can compare yourself when NPD comes out, but I think it is very good for what the site tries to do. Sure VGChartz is off every once in a while, but most the time they are right on with hardware. As time goes on, the numbers get adjusted, and this is the best place for accurate historic sales world wide. Think of it this way, when the sales first come out, they are within 20% of real life, and as time goes on, it gets much closer to within 5%. So numbers from this week may be off, but numbers from 4 weeks ago are spot on. Not to bad for Brett doing this as a hobby for the past 2-3 years.








