6.15 Other changes in volume are flows with different functions. One important function is to allow certain assets to enter and leave the system in the normal course of events – e.g. entrances and exits of naturally occurring assets. This is important for recording the discovery, depletion and degradation of natural assets. A second function is to record the effect of exceptional, unanticipated events that affect the economic benefits derivable from assets.
6.16 The other changes in volume cover nine categories: