As for having data with me right now as I sit here, no, but I have done that research and that is why I was able to summarize it in that sense.
My statement also did say that even when they are employed it would not be at the same level as other immigrants who may have the skills. If you think about it, if you cannot speak one of the official languages of the country, what would your income level be, because you don't have the basic knowledge to communicate?