Well, I'd interpret those numbers as: ~56% for, ~4% opposed, and ~40% unknown.
81,283,501 for Biden, 74,223,975 for Trump, 158,429,631 total votes, 252,274,000 as best proxy for eligeble voters (18+ us pop) per [1]
[1] https://www.fec.gov/resources/cms-content/documents/federale...