#### Answer

The least number of awakenings for women are at the age of $8$ years, the average of which is $1$ time.

#### Work Step by Step

We can observe from the line grap, that at 8 years of age, women have the least number of awakenings during the nights.
And, the average number of awakenings at this age can be observed to be as 1 time.
Therefore, the average number of awakenings at the age of 8 years is 1 time.