Use TimePlot (http://www.simile-widgets.org/timeplot/) to implement an alternative to the gnuplot generate
time-series graphs here:

http://www.rtems.org/ftp/pub/rtems/people/joel/coverage/erc32.html

I think you could do two timeline plots which capture the information our 8 png's have.  This would be in addition to the pngs.

The script that generates these graphs is in the cvs module rtems-testing in the directory rtems-coverage.  You will have to grab a few erc32*.tar.bz tarballs to have test data