Ask HN: How many Dvorak keyboard layout users in the wild?

I'm wondering if a Microsoft or an Apple employee has some rough estimate of the amount of Dvorak users compared to Qwerty and other keyboard layouts?

It would be nice to have a list, I'm not even sure what would be at the top? US Qwerty?

I'm not interested in the pros and cons of the layouts, just a rough estimate of adoption.

Thanks in advance.