I hit the WSJ paywall so I don't know what they say about it, but according to the AP article on this topic the state's population estimates don't use census da

I hit the WSJ paywall so I don't know what they say about it, but according to the AP article on this topic the state's population estimates don't use census data >The state's population estimate comes from a number of sources, including birth and death counts, the number of new driver's licenses and address changes, school enrollments and federal tax returns.