How mant units of each sega console sold in the US?

I'm having difficulty finding accurate numbers.. Does anybody know?

it doesnt have to be every variation of every console, just lump em all together.

Sega Master system (all variations)
Sega Genesis (and all variations)
Sega Game Gear
Sega CD (and all variations)
Sega Pico
Sega Nomad
Sega 32X
Sega Saturn (model 1 and model 2)
Sega Dreamcast

 

I second that, all the numbers I've seen are always estimates