In the Diagnostics → Performance page you can inspect a statistical measure of the performance of PMA.core. The page displays the average time it takes for PMA.core to serve a request. The page is split in two parts one for hourly averages and one for daily averages.

• Number of requests: The number of requests served by PMA.core
• Mean: The average time to complete a request
• Deviation: The standard deviation of the time taken by the requests

Those statistical measures are calculated for today, yesterday, two days ago, three days ago, four days ago, a week ago and a month ago.

That way you can inspect the performance of PMA.core over time and visually detect any significant statistical differences in the average or the standard deviation.