Range of disk space bar graph

I have few HDDs and many of them are most time over 80% full (I work with large files). It will be nice feature if I can set range of bar graph not from 0% to 100% but, for example, from 80% to 100% (or any other range).

PS. Bar graph in status bar of course - {bg}.

You could set the graph to show free space as a percentage of a fixed size. But you would have to choose a fixed size that makes sense for all drives, or be OK with the graphs not always being useful (e.g. when looking at a small USB stick).

If that compromise sounds useful, the way to do it is described here.

My HDDs are different capacity, so it's not a solution for me. I just want to see last x%. If it will be possible to do - I'll be happy.