FIM 2010 R2 - User history report - Almost duplicate rows

I am using a default User history report.

I noticed that report return "almost duplicate" values for at least Delete operation types. So basically there are 2 rows for deleted person. The only difference is that Attribute Value column is empty in another row and in another row there is a value. Like below.

Username, Operation type, Attribute name, Attribute value
User1, Delete, ObjectID, 234234-234-234-234
User1, Delete, ObjectID,