Update the value saved in a tinydb if I change a constant value or parameter

i have an app that save in a list (importe_km_recorridos) the result of multiplying a number added in a textbox (TB_km) by a constant value (0,21).

Afterwards, I save this value in a tinydb with the tag importe_km_recorridos.

Captura de pantalla 2021-09-13 201326

Now, The problem is the following: The constant value has changed, now is 0.25, I have changed this value by hand in the code of the app. Then, the events saved previously do not update the value of multiplication, but they keep the old values.
How can I do to update the values stored in the database? How can the users update this constant value and it apply to older values generated with other constant value??

Thanks.

If you store the value after adding the multiplication by 0.21 to the list, if you use the tinydb store block, automatically the previous value will be overwritten