Number of systems on ships

I have a rather odd question. What are the average number of systems people
put on a ship? For instance a Mass 18 FTL escort could have 9
c-bats but what is the average number of systems?  I'm curious as to
what sizes I would need to make a ship diagram for the "average" ship.

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> I have a rather odd question. What are the average number of systems

I've noticed that the average number of systems I stick on ships is ~1/4
to 1/5 the Mass of the boat in question (eg, a Mass 60 ship might have
12 systems put in it; a Mass 14 boat might have only 4). Very few of my ship
designs seem to stray from this (unless they're special-designed ships,
of
course ;-)

Mk