Approximately 15% of the modern workforce performs night shift work.
"we have 15% of workforce who does night shift work, and they are the ones who actually enable the rest of us to stay awake." (said at 1:07:18)
No published record matching the claim that approximately 15% of the workforce performs night shift work was located; this does not prove the claim false.
Official statistics and occupational health reviews widely estimate that approximately 15% of the workforce (commonly cited between 15% and 20% in the United States and Europe) engages in shift work or regular night shifts.