Number of houses that use wood heat in your city. See example for 44880 Ohio

1.4% in my zip code. That's about 8 on 602 houses. Sounds plausible. Although I don't any are heated 100% wood there are a few that I know burn wood mist of the time.

 

Couldn't seem to get any data for my city, but I can tell you that it is less than 1%. Back in the 70's and 80's there were a lot of wood burners. But not any more. Being fire chief, I kind of keep track of the wood burners so I am familiar with their place if God forbid they have a fire and I have to go there. We have at least one a winter. Just aren't many of us left though.

 

Google "61953 city data" and it goes right to it.