The library's "reference collection" is in room 109. That is the room between the library desk and the stairway to the library's second floor.
It is called a reference collection because the material in it can be referred to (i.e., used) but not checked out. The material consists of things like dictionaries, encyclopedias, and, importantly for you, large books full of statistics.
Some reference books that could be useful for statistical research include
Many of these contain incredibly rich sets of statistical data, and background information useful for interpreting that data. Just look at one page of the table of contents of the Historical Statistics of the United States. You will see that there are introductory essays and tables on a range of educational, health, and social assistance topics: