Study the following graph that shows the number of boys and girls who appeared for the Class X examination in a school XYZ, in different years.

The average of the number of boys who appeared in 2011, 2013 and 2015 is what percentage less than the number of girls who appeared in 2012 (correct to one decimal place)?

A

8.1%

B

8.5%

C

6.9%

D

7.7%