AMC8 1991 Problem 18

The vertical axis indicates the number of employees, but. the scale was accidentally omitled from this graph. What percent of the employees at the Gauss Company have worked there for 5 years or more?

Answer Choices
A. 9 \%
B. 23 \dfrac{1}{3} \%
C. 30 \%
D. 42 \dfrac{6}{7} \%
E. 50 \%