Rate

V1

V2

Mean

R1

6.4^c

5.6^c

6^c

R2

11.8^a

11.3^a

11.5^a

R3

8.5^b

9.7^b

9.1^b

R4

8.9^b

10.2^b

9.5^b

Mean

8.9^a

9.2^a