First look at the image:

You can see from the image that the apt process is downloading the repository updates, the one at the moment is one that is 5.406 KB of size, to which the download as only gotten 1.831 KB which is 34% of that package. At the far left, in the same line we can see the suppose "total" download percent, which shows 82%.

I would think that this is 82% if the total packages needed to download, but then I would be mistaken. After downloading the package mentioned above, this 82% instead of going up, might go down like 73%. Even if it get to 99% does not mean it is 1% from finishing. This 99% could go down when downloading the following package.

So since this left most percent does not actually stand for the total package percent, what does it stand for since it confuses me when waiting for a download or checking the downloads and seeing it get to 95%, then back to 60%, then up to 80%, then down to 76% and so on.

So my questions are:

Where is the actual TOTAL percent which shows how much has been done and how much is left?

Does adding 3rd party PPA (Xorg Edgers, webup8, xbmc...) influence in the correct check for the total percent?

Why the abnormal jumps between percents where they go down instead of up (eg From 85% to 81%)