From: Teaching evolution in U.S. public schools: a continuing challenge
2007 (N = 926), %
2019 (N = 753), %
Not covered–0 h
75
82
1–2 h
17
9
3–5 h
4
2
6–10 h
1
11–15 h
0
16–20 h
20 h or more
No answer provided
3
Total
100