They are ballpark numbers. But it does indicate that nowhere is near herd immunity. New York City might be closest at 2 million infected out of 8 million people (if i had to give a ballpark number)
Sweden Infectious disease chief just claimed Stockholm is weeks away from achieving herd immunity, who knows who´s right, and how they came up with those numbers in Sweden (The Telegraph is also behind a paywall, let me know if I missed important information)
https://www.telegraph.co.uk/news/2020/04/18/stockholm-will-reach-herd-immunity-within-weeks/