From UCSIC we know:
immigration age = age at the time when first time* visa number becomes available after I-140 is approved - the time period during I-140 was pending
*USCIS specifically stated that in case of visa number availability retrogression, the earliest or first time visa number becomes current is used for age calculation.
But , when Wgzmb co-file I140/1495 (including his or her son), the visa number are all current for Employment Based cases. The retrogression occured later after june 2005 when Wgzmb's I140 had already been approved. So how to count "earliest or first time visa number becomes current is used for age calculation" ?