[Ger-Poland-Volhynia] why would passenger ship carry just two families?

[Charlotte Dubay]

Hello again to listers,
Another question:
My Heimthal ancestors came to America on the SS Stuttgart I, leaving Bremen,
arriving at Baltimore in 1894. Ship not to be confused with SS Stuttgart II, 
that was manufactured 20 some years later, by a different builder.
 
(I was fortunate to find both their manifest and a photo of the ship 
more than 10 years ago - when online searching was pretty much free.)

But I have often wondered why on this particular crossing, the ship only carried 
2 families...20 passengers.

I had done some searching on the ship itself, and it carried full 
passenger lists on other crossings. 

Thanks for any ideas on why a ship would carry so few passengers. 
Cargo that trip perhaps?

Charlotte DuBay
hoeserhistory at aol.com