This report shows the average, peak, and 95th percentile utilization for all interfaces and latency on the selected devices.
The 95th percentile is a statistical function. In basic terms, this value represents the peak value of the variable after the top 5% of values are discarded, giving you a more representative picture of the “high-water mark” while excluding anomalous spikes. Note that for short time periods, this report may return the same value for the peak value as for the 95th percentile. This is a normal effect of the statistical calculations and is not an error. For best results when capacity planning, this report should always be run for a period of one month or longer.
Found on the Built-in Reports page (Reports → Built-in).