I've seen anywhere from 60% to 80% of the population quote for viruses. At any rate, assuming some resilience to future infections (that exhibit symptoms), the more people that have had it, the less it is able to travel.
New York is a total outlier from everywhere else in the country, but they have probably had a way higher percentage of infections too. I saw that one place in Massachusetts that was particularly hard hit had 30% of people with antibodies. It's seeming likelier and likelier that this will end up at .5% or less, and I've seen estimates of .12% to .2% mentioned already.