Understanding Society User Support

Dear Understanding Society Team,

I am working with household level income data and I would like to adjust that data with the number of working age people in a given household. However, I noticed that the nwage_dv variable has a significant portion of zeros for this variable.
How might this be possible as zeros indicate in my understanding that the number of working age people in a household are none.
I would appreciate a brief clarification.
Thanks, and have a good evening,
Best,
Nico