An Instructor can see Course stats for her course only. Since calculating Statistics for the course is a complex process, statistics for the course needs to be manually activated by clicking the Calculate Stats icon at the bottom of the course stats screen.
To see Courses stats Instructor needs to go to Single Course -> Admin -> Stats
If Stats for the course are not calculated or to recalculate the stats the Instructor can simply click on the Calculate Stats icon
The Course stats then appear on the Course Stats screen.