Hi,

the numbers in the Course Activity Report (report_outline) are calculated from the log entries which are available at the time when the report is requested. Thus, the output is directly coupled to the log lifetime.

The user is informed about this fact with the line saying "Computed from logs since ..." at the top of the report.

Unfortunately, a teacher does not have any possibility to define which log entries should be considered when the numbers are calculated.
For example, we have a Moodle installation with a very long log lifetime and a course on this Moodle installation has run for several months now with several cohorts of students using it. If a teacher looks at the report, he can't really tell if the current cohort is using the course properly or not because he only sees the total numbers for the whole course lifetime.

I would propose to add a filter widget to the top of the report to control
a) the start date from when on log entries should be used for computing the numbers
b) the end date until when log entries should be used for computing the numbers