You are not legally obligated to answer personally identifiable information in a census form. The only purpose of the census per the USC is to enumerate the physical residents of a domicile. You tell them there are 2 adults in the residence, and you’re done.
I took a black Sharpie to my form a few years ago and blacked out everything in the form except the number of people in the home. This was to prevent them from trying to fill out any information that I left blank, which they’ve done in some highly publicized incidents. When the drone came to my door, I told them there are 2 adults in the residence, and they never came back again.