Year Narai MK V introduced

Looking through Sailorman newsletters to find out when the Narai MK IV was introduced and any information about the design aspects talked about when was announced/introduced, but not finding it yet.

Anyone know what year the Narai MK IV was introduced, would like to read what was said about it in Sailorman.
No special reason, just interested in the history of the Narai MK IV.

Cheers, Allen