InspectIT provides access to old data via the historical data menu. This menu is opened by the little grey symbol to the right of the view. After setting your data you need to hit the blue refresh button.

Using the sampling rate

The sampling rate defines the aggregation that should be used on the data prior to presenting it. If the user requests to see a big timeframe it is usually meaningful to select a higher sampling rate. This means that data of multiple intervals are aggregated. If you choose you can always slide the slider to the left to "no aggregation", then all intervals are presented as is. See the pictures below for some examples from "coarse" to "no aggregation"