Creative Commons license distribution

The Creative Commons has create licenses to help people share their information more freely(i.e., publications in the broadest sense of the word). An article on license distribution notes:

Last week we mentioned there were over 5 million web pages linking to Creative Commons licenses. This week, it has come to our attention that Yahoo! has updated their index to find well over 10 million web pages that link to our licenses.

The accompanying chart can be viewed here. The most popular license (37%) is referred to as "Atribution - Noncommericial - ShareAlike".