DRA Testing/Reading

I am working on getting my DRAs done for the end of the year. I have found it time consuming to DRA 25 students several times to get their independent reading level. I did recieve some advice about pulling a small group of students that are at a higher reading level to take the test in a small group at my table. This has helped get through more students each day and not have to wait for them to come to my table to test. The problem I am still having is picking the level to start the student at and then giving them at least two tests if not more to find their independent level. I am not sure if there is something that I am doing wrong or missing that could help with this situation. I also feel that I am testing students who don't need to be tested again at the end of the year who are reading well above grade level. I have a high reading level group of students this year and feel that this is just more testing that they have to go through only to be tested again in the fall.