Instruction 2 -Referring to Instruction 2

Short Answer

Instruction 2.8
Given below is the stem-and-leaf display representing the amount of detergent used in litres (with leaves in 10ths of litres) in a month by 25 drive-through car wash operations in Auckland.
$$\begin{array} { | l | l | } \hline \text { Stem } & \text { Leaves } \\\hline 9 & 147 \\\hline 10 & 02238 \\\hline 11 & 135566777 \\\hline 12 & 223489 \\\hline 13 & 02 \\\hline\end{array}$$
-Referring to Instruction 2.8,if a percentage histogram for the detergent data is constructed,using '9.0 but less than 9.9 litres' as the first class,_________% of drive-through car wash operations use less than 12 litres of detergent in a month.