Who?
Who would might want to collect these statistics or already collects it?
What?
What is the subject or topic?
What populations or units of analysis are needed?
When?
When is the time frame?
Is that time frame realistic?
How often were the statistics compiled?
Where?
Is there a geographic component to the topic?
Are statistics for the geographic area realistically available?
If not, are there other possibilities?
Ways to find out
Statistical Abstracts (can locate via Library Catalog)
Government Statistical Agencies (see link on right for National Statistical Offices)
Literature Search (including newspapers!)