My understanding of the NY/NJ trajectory is that the people who didn't get it in March/April were being particularly careful and still are.
20% already had it, 30-40% probably aren't susceptible (based on data from confined ships), from the reaming 40% only a very small portion are at risk of severe symptoms, and these people are probably extremely careful. The portion of the population that isn't capable or interested in avoiding it already got it.