If you check the "Record Scores for Single Sets" box, then WeBWorK will generate scoring files for each set that include scores for each problem. This generates one file per set. If you want multiple sets you'll probably have to combine them yourself.
Note that the scores for the individual problems will not be displayed in the browser. They are saved to a file in the scoring directory of the course (/opt/webwork/courses/courseId/scoring). You can access these files from the file manager. There are three files generated. One with totals that contains what is displayed in the browser. That one will be named what you tell it to be named in the browser. The other two files contain the individual problem scores. One has more detail than the other.