The School Enrollment Count selection is under "Enrollments" In the Data Points Tab.
Choose Between Dates, then the detail columns to include.
Click on "Styles"
Set up Column Configuration
Set up Risk Value Contributions
Manage Contribution Set
Choose a Specific Date or School Year Contextual Date
School Year Contextual Date > Select School
Choose Term, Starting Point, and period for final adjustment
Save Contribution Set
Save Column Configuration
Save the Column
Finish Risk Configuration as required.