Right off I wanted to disagree about the preprocessor use for CSS. I just can't see that something like those has taken off so much that it's on the same level

Right off I wanted to disagree about the preprocessor use for CSS. I just can't see that something like those has taken off so much that it's on the same level as something like jQuery. But then it made me curious, I can't say that since I have no numbers and it's just an assumption. Are there any indicators of how popular tools like less or sass have become as opposed to regular CSS?