The first snapshot will have these characteristics. If any of the snapshot you examine has any of these characteristics then it is the initial snapshot of this artifact:
1.
_SnapshotType = "Create"<Please see attached file for image>

2.
_SnapshotNumber = 0<Please see attached file for image>

3.
_PreviousValues will have all fields =
null.
<Please see attached file for image>