Table: northern_state_conference
Columns: school_ihsaa_id
location
mascot
enrollment
ihsaa_class
county
year_joined

Question: What is the sum of enrollments for schools located in Culver?
SQL: SELECT SUM("enrollment") FROM northern_state_conference WHERE "location" = 'culver'

Question: Which year did the school with enrollment of 413 join?
SQL: SELECT "year_joined" FROM northern_state_conference WHERE "enrollment" = 413