I always thought during the 30's to 60's that there were like around 7 crews for Genovese and Gambino families and 4 for the others since a captain was a more influencal and powerful position than today. And from then to now the amount of crews/Captains increased.

"You shouldn’t be embarrassed by your wealth. This contempt for money is another trick by the rich to keep the poor without it" - Michael Corleone

"You don't have to count the dead to understand the business of the Camorra" Gomorrah, Roberto Saviano