How do I copy the table and fill in the boundaries for each class?

See table and explanation below
Explanation:Given:
A table showing the age in years and their frequency
To find:
To fill in the boundaries for each class
To get the boundaries of each class, we will have a lower boundary and upper boundary
lower boundary = lower limit - 0.5
upper boundary = upper limit + 0.5
class boundary = (lower boundary - upper boundary)