They weigh a kilo for each "personality" they have

All of them.

You mean institutional living?

Yes, mental homes.

16 sound REALLY high but i've not read into it enough to know either way.

It's an average of 4,500 cases ever reported.

That still sound rather high. I wonder if they are counting the 100 and other fringe high numbers in their average (which is a definite big no no in statistics)

I just got it off of the Wikipedia page of DID (Dissociative Identity Disorder), but it is true that, the most recorded personalities in a person has never 100.