Let's say we have a table of student records. From that information, we want to find the average grade per course per year.
| Student ID | Last Name | Year of Enrollment | Course | GPA |
| 1 | Johnson | 2012 | CSE | 3.47 |
| 4 | Hayes | 2012 | CSE | 3.82 |
| 2 | Turner | 2012 | ECE | 3.34 |
| 3 | Jones | 2012 | ECE | 3.54 |
| 5 | Lindsay | 2012 | ECE | 2.99 |
| 6 | Smith | 2013 | CSE | 3.12 |
| 10 | Frick | 2013 | CSE | 3.53 |
| 11 | Jones | 2013 | CSE | 3.78 |
| 12 | Zelaya | 2013 | CSE | 3.94 |
| 7 | Wallace | 2013 | ECE | 4.00 |
| 8 | Jabbar | 2013 | ECE | 3.65 |
| 9 | Borg | 2013 | ECE | 3.32 |