Describe the bug
When changing the histogram buckets in the Statistics and Charts page, you frequently end up with an incorrect total of entries. This does not apply to the overall histogram, just the manual grading and autograding histogram.

Expected behavior
The total number of students displayed should remain the same.

To Reproduce
Steps to reproduce the behavior:

1. Go to any gradeable with completed grading.
2. See total before entering a bucket.
3. Change bucket to something larger than the bucket default (see bottom of the histogram for default)
4. See error

Configuration

• OS: Linux
• Browser: Opera

Screenshots

For example, the original histogram has 60 entries but the updated histogram only has 49.

Additional context
I only observed this on [sample][Autograde and TA Homework (C System Calls) Grading], other assignments may not have this behavior.