The preimport statistics include the number of records for each supported entity. The total number of records for import is the total number in the batch minus the records that were removed and not to be imported, as a result of actions taken on duplicates from the batch de-duplication process. See: Batch De-Duplication.
The postimport statistics include the number of records that are:
Insert: Imported as new records.
Update: Imported to update existing records.
Merge Request: Included in a System Duplicate Identification (SDI) batch for merge consideration.
Automatic Merge: Automatically merged. The merge occurs after all potential duplicates are inserted, so the total number of records imported includes these records.
Note: The statistics for Insert and Update do not include parties that are also included in a SDI batch or automatically merged.
You can compare, for the entire import batch before and after import, the number of records removed or imported.