Oh dear.
The last time the citizenship question was on the standard census form was 1950.
Since then, some form of the question has appeared on either the long form, sent to 16% of households every 10 years, or the American Community Survey sent to 3.5M randomly selected households each year.
The question wasn't on the 2010 census because the long form had been dropped as it's been replaced by the ACS.
BS! Now it’s clear you are parroting leftist talking points.