A company has 50 employees all working in the same building. As part of their safety procedures, a fire drill is carried out with the total number of employees who have left the building recorded every 10 seconds. The results are displayed in the cumulative frequency diagram below.
The company has the following policy: 'in the even of a fire, at leat 90% of the employees must have left the building within 1 minute.'

Did the fire drill procedure meet the policy above?
You must show all your working.