[Berkman(1998-2005) Belief in Teaching Only Evolution(%): 20〜24% 25〜29% 30〜34% 35〜39% 40〜45% ]
[Source: Berkman, M. B. & Plutzer, E. (2010). Evolution creationism, and the battle to control America’s classrooms. New York, NY: Cambridge University Press. via Belin and Kisida]