Unlabelled Gauge markings

[Eric Harman <ericha@wrq.com>]

Very embarrased to ask this neophyte question.  

When you have a gauge ('91 200 Q oil temp, for instance) that has
a labelled mark at 60, an unlabelled one, then a labelled one at 130,
what is the value for the middle mark?  Is it just directly between the
two?  What if the mark is geographically a lot closer to one of the
labelled marks?  So, is my middle mark, which is the one that it rides
at most of the time really 95C or 203F?
   95 = (60+130)/2

    -ericha (Eric Harman)
    Seattle
    '91 200 Quattro (for sale), '90 Mazda 626 Touring Sedan GT