What is an invalidation in a buffered table under ST10

Hello,

I use SAP 4.6c.

With ST10 you can see the table call statistics.

The first column shows the number of invalidations. Whenever a table is changed or a transport is done which affects the table, it is marked as invalid. If a change on a fully buffered table is done, the whole table is marked as invalid in the DDLOG file (number of invalidations increases to 1). If a generic buffered table is changed, only the affected regions are invalidated(number of invalidations increases in dependence of the number of affected regions). If a single record buffered table is changed, the corresponding entries are invalid ( the number of invalidations increases in dependence of the number of affected entries).

But some fully buffered tables have 40 invalidations for example although they only have 5 changes. The number of transferred rows is zero. I do not understand this. If a transport has been done, this would affect both, the number of invalidations and the number of affected rows as well. But obviuosly, this was not the case. If one change is done, only one invalidation is count. 5 Changes can not cause 40 invalidations.

Does anybody understand this?