If you read that page carefully you'll note that he's using a modified version of MRTG that doesn't average its samples. As it says:
No. The only change he makes the MRTG is to display the 95th percentile values he computes.
This is a patch to add 95th percentile metering to MRTG. This is not as simple a feature as one might think. MRTG normally saves only one day worth of 5-minute samples. It is not possible to accurately calculate the 95th percentile without having all of the samples for a one month period. In order to calculate the 95th percentile for a 30-day period, it is necessary to save an entire 30 days worth of the 5-minute samples.
Right, so he has to make backups of MRTG's log file in order to have sufficient history data.
MRTG does not do that by default, nor does Cricket, nor will any tool using RRDtool as an underlying database.
MRTG does not do *what* by default? DS