With each downturn, the oil industry has seen its pool of workers shrink.

The bottom line is that the pool of diverse critical opinion to which readers can turn has been shrinking.

But the pool of people available to do volunteer work - especially to take on big jobs - has shrunk.

Alas, the pool of corporate talent has shrunk since the 1970's.

As a result, the pool of bidders shrank and costs shot up.

There were many applicants the first year, but since then the pool has shrunk.

In the next decade, the pool of workers entering the job market will shrink to "the lowest since the 1930's," she said.

This is because the available pool of labor has shrunk.

As the costs rose, so did tuition, but the pool of students was shrinking.

Even as the pool of workers shrunk, demand continued to grow rapidly.