CNN's ratings problems just keep getting worse.

The network had its lowest-rated month in over a decade in April. That prompted stern warnings from the top that CNN has to improve its numbers.

Yet Tuesday brought the dispiriting news that CNN had its lowest-rated week in primetime in a staggering 20 years last week. Just 395,000 people tuned in to watch Anderson Cooper and Piers Morgan. The total day numbers were not much better: CNN had its third-worst week since 1997.

Luckily, the network continues to turn a very healthy profit. And, as Morgan can attest, CNN's ratings have been on a bit of a roller-coaster ride lately:

BREAKING NEWS: My #CNN ratings rose 350% last night on Tuesday's number. #HalfwitToGeniusIn48hrs — Piers Morgan (@piersmorgan) May 18, 2012