If you go to Reporting>Reports>Attendance (tab) you can use the Code Count report.
Select the one code you wish to report on, and the date range, then all students with that code on that day will be shown in the report.
If you wish to note all codes used in a specific period, you could use the All Codes by Group report.
This will give you a breakdown by year group and form for each code used, which can be run by Count or Percentage.