It's "The Case of the Disappearing Data," but there's no need to call in Nancy Drew. It's quite clear that the cause of this disappearance is budget cuts. The Bureau of Economic Analysis can no longer afford to gather and publish all the statistics it has been producing over the last several years. You can see details about the data no longer being collected in this BEA blog post:
situation begs the question, if the economy has gotten so bad that we
can no longer track the economy, how will we know when it gets better?
Solving that mystery may require someone even smarter than Sherlock