** Using WeBWorK **

I am trying to see how we can identify in the grade list file which students actually took their exam and scored 0 and those that just did not take or submit their exams. 

I can see in Student Progress that some students took the test and scored 0. But in the grade file, I cannot ascertain which students scored 0 and which were absent since they are both represented by a 0 grade. 

For example I know that these students took their tests because Part 2 has a non 0 value. But there are potential cases where a student might get a 0 on both parts.