All absences due to ill health are recorded on the Defence Forces Personnel Management System (PMS). This is a live system which is updated on a continuous basis. While the introduction of this system has improved the maintenance and tracking of sick leave absences for members of the Permanent Defence Force, there can be discrepancies in the figures produced from reports run on different dates.
The military authorities advise me that this can arise for reasons such as the clearing process required when certificates from civilian rather than military medical personnel are relied upon or where a medical board revokes sick leave. With the passage of time, the variation for a particular year reduces.