freebsd-update percentage indicators - what are they, why are they so random?

[Mike Brown]

I'm using freebsd-update to upgrade my system to the latest minor release.

At a couple points in the process, I get weird status indicators (percentages) 
showing me that something is happening:


Fetching 1 metadata files...  70.5%
done.
 70.5%
 70.5%
 74.2%
 74.2%
 81.7%
 81.7%
 70.5%
Inspecting system... done.



Sometimes these numbers are negative, and although not entirely random, they 
don't seem to follow any particular pattern... they don't creep up from 0 to 
100, at least:

Preparing to download files... done.
 -4.7%
 -8.4%
 -9.6%
 35.4%
 30.6%
 30.5%
 45.2%
 43.4%
 43.0%
 68.1%
 68.2%
 68.2%
 44.4%
 43.0%
 43.0%
 72.0%
 71.9%
 71.9%
 69.1%
 69.0%
 69.0%
 72.0%
 71.9%
 71.9%
 69.1%
 69.0%
 69.0%
 52.2%
 50.2%
 49.9%
 53.4%
 56.8%
 57.5%
 59.0%
 55.1%
 56.0%
 91.4%
 94.5%
 94.3%
 90.4%
 94.5%
 94.3%
 54.8%
 54.6%
 55.3%
 28.8%
 24.9%
 24.2%
 57.0%
 53.3%
 55.1%
Attempting to automatically merge changes in files... done.


What is the point of these numbers? Does everyone see them, or is it just me? 
Are they supposed to be on separate lines like this, or are they supposed to 
overwrite each other one line?