Overall sample

Experimental sample

Control sample

F

p

F

p

F

p

Comparison between level 1 and level 2

0.46

0.008

1.09

0.02

0.71

0.02

Comparison between level 1 and level 3

1.61

0.000

0.06

0.002

0.19

0.000

Comparison between level 2 and level 3

3.62

0.012

0.45

0.42

2.25

0.001