How is MT data calculated in Analytics?

I was wondering exactly how MT percentage is calculated in Analytics. For example, if a user just adds a space at the end of an MT segment (and doesn't touch any other parts of the segment), does that mean that the segment is counted as being 100% post edited, or is it then computed as being mostly MT (say 98% MT) and slightly (say 2%)  post-edited for calculation of MT data in Analytics?

Best,

Mike