Data was split into two separate files--one for each of the libraries studies. Data was subsequently loaded into SPSS 25.0.0.1 64-bit version for Windows.
The HomeGame variable was recoded so that the absence of a home game was coded as a 0 and the presence of a home game was a 1.
Data was reduced down to just five variables: Year, Week of Semester (WeekSemester), Home Game (HomeGame), Gate Count total (GateCount) and Library.
Initial exploration of the difference between the means for Saturdays with home games and Saturdays without home games was performed using simple box and whisker plots to get a visual feel for the difference as well as the spread. Although some outliers were clearly visible, these were left in the data sets.
Independent Sample t Tests were performed for each of the two datasets and confidence intervals were set at 0.95.
The SPSS syntax for the recoding, exploratory analysis, and Independent Samples t Test is available on this site.