Here are the percentages of students transferring to homeschooling from each sector:
Traditional Public: 15%
Private: 16%
Charter: 13%
Question 1: "What type of school did your youngest school-aged child attend before the COVID-19 shutdown?"
Question 2: "What type of school will your youngest school-aged child attend after the COVID-19 shutdown?"
If that change actually occurred then the homeschool population would nearly quintuple in size.
The parents who selected into this survey could be the most likely to switch out of brick-and-mortar schools.
These results are therefore likely upper bound estimates of the actual transfers that will occur.
The expected losses to brick-and-mortar schools are larger than I expected, even for this nonrandom sample.