This was Tomoaki's first blog post of this series: Friday with International Community Update – Progress in each language (Dec. 2012).
Tomoaki added in the specific language instances. For example, the Portuguese community got their own language instance, so all their newer articles were being posted there. That's why they jumped up 500 articles this month. Also, Russian had their own instance, which is why they jumped up 90 articles.
For October, I brought Tomoaki's list over to our Wiki Ninjas blog: Stack Ranking the Languages on TechNet Wiki.
In the first chart, we should point out that English was far greater, maybe about 5-6K (it just wasn't tagged much yet). Portuguese had already made a huge push (led by Yuri and MVPs) to break the 1K articles barrier. They broke it quickly in 2011.