O2 sensor bias

[Alex Samson]

>Ok this isn't really true of an O2 sensor, but just pretend for a
minute.
>What you want, roughly, is an O2 sensor who's output crosses >through
the 450mv range at say 16:1 rather than 14.7:1. 

A question that has remained unanswered in my head for many years now is
if the O2 sensor outputs 0.45v at 14.7 mix,  what is the mix ratio when
it outputs 0.8v? or 0.9v? or 0.2v?  Does anyone have a graph of a common
O2 sensor characteristic of Voutput vs Fuel ratio? I have searched for
Bosch data on this but have never seen it.