This is something that was first put out by some Muslim group in LA - I think the LA Times had a story on it. Then it was published in the NY Times. Many people pointed out that all the "statistics" came from CAIR or its local group, and particularly its spokeswoman, an American muslim convert who appears on the university lecture circuit announcing the glories of Islam and how happy the slaves - er, I mean, women - are under it.
One of the favorite tactics of Muslims is to announce that the whole world is "converting" and to inflate their numbers. It is not surprising that the liberal press loves this and features it prominently, no matter how dubious the source.
That is, of course, true for all groups as part of our corrupt nature, but in Islam it is codified as a commandment – an obligation to lie and deceive the infidel (also known as taqiyya, as mentioned in the article).