DID in particular is sampled at about 1%. I’ve included an excerpt from the previous link that states this. That paper seems to align with clinical perspective, as it’s the same number that McLean Hospital uses in their public communication. McLean is a psychiatric teaching hospital as part of Harvard Medical. It is one of the few organizations in the country that specializes in treating severe trauma disorders.
“Random samples of the general population in Canada and Turkey (female sample, 50% of whom were illiterate) found a life-time prevalence of DD of 12.2% and 18.3% respectively. A general population study in New York State found a 1-year prevalence of 9.1% for the DD.2,32,39 In Canada and New York, prevalence of DID was 1.3% and 1.5% of the population. In Turkey, the lifetime prevalence of DID was 1.1%”