Corelations between expanded size and regular size

When in the most expanded state of pumping or jelking etc, I have started to notice certain measurement differences.
So, measuring in at
7.4-7.6 BPEL
7.9-8.1 BPEL fully expanded
7.8-7.9 After full expansion during erection…

It does seem to me that size increases often in .25 inch increments consistently.

My gains have only begun so I can’t tell whether or not this expansion percentage remains constant but I am sure there are corellations all over the board and obviously everyone is different so my question is, what have you noticed in size differences between full expansion and erections freshly after expansion?