By the 1980s, when the dsm contained the first formal code for the number of diagnoses for this condition in north america exploded from 2 per decade to more than 20,000.

The DSM contained the first formal code for DID or the  Dissociative Identity Disorder. 

At least two particular characters or identity states are available, each with its own particular generally continuing example of seeing, identifying with and contemplating the earth and self. 
DID, otherwise called multiple personality disorder (MPD), is a mental issue portrayed by no less than two particular and moderately continuing characters or separated identity states.

I'm not 100 percent sure i say 7 is your answers