What are the numbers running down the left side of the page?

Typically the number of people in an organization can run from 10 to 50.

A number of people were running to it as well.

Some days, you don't have the numbers to run offense and defense in practice.

She had seen a number of love affairs run their course.

A number of men, women and children were running toward it.

The number of her short stories runs into over 3000.

Indeed, some believe that the true number runs into the thousands.

Later the class became 319 and the numbers ran from 319.001 to 319.103.

No good; he couldn't keep that sound out and the numbers were still running through his head.