You file a corrected Form 8606 only to change your prior years basis.
every time you do a backdoor Roth your traditional basis starts with zero and ends with zero.
you wouldn't have to file a bunch of forms 8606 to show that your basis was and still is zero.
If you insist,
Note: when you file 1040-X and no dollar amount are changing, leave Lines 1-23 EMPTY.
Do not include your old 1040 nor your revised 1040 because the Form 1040-X reflects any changes there and becomes your new tax return. In this case, nothing is changing.
@Anonymous
