According to this new release from the Evans Data Corporation, certain technologies are being more well used in other areas besides in North America - including PHP.
There is a greater disparity with PHP use in Emerging Markets. The largest number of developers using the language can be found in Eastern Europe (39%). India and Brazil have similar usage at a little over 31%. In contrast, only 21% of Chinese developers are utilizing PHP. In North America, 35% of developers are using PHP.
They also talk about the usage rates of a few other technologies, including Flash, Ajax, Windows, and Linux.
Cal Evans also mentions these trends in this post on the Zend Developer Zone as well as linking to the full EDC report.