Nest Binding - Unknown person

Tags: #<Tag:0x00007f616e4f9800> #<Tag:0x00007f616e4f9580>

I see in the NEST bindings that you can check has_person to see if the last event has a person in it. But is it possible to count the events that have an unfamiliar person in them? I’m the kind of nerd that would like to start a persistent counter to keep track of how many unknown people swing by. Which will basically tell me how many Amazon Prime deliveries there was, LOL.