In text history mode, the data on the screen is the real data recored. If it is recorded in Every Second, then each data is each seconds count. If it is recoreded "Every Minute", then each data is the CPM reading at that time. If it is recorded "Every Hour", then each data is the average CPM in that hour.
The data type is indicated at the end of data and time. (S):every second data. (M): every minute data (H):every hour data.