Table: lake_ath_conf
Columns: school
location
mascot
county
year_joined
previous_conference
year_left
conference_joined

Question: Which Conference Joined has a Previous Conference of northwestern, and a Mascot of oilers?
SQL: SELECT "conference_joined" FROM lake_ath_conf WHERE "previous_conference" = 'northwestern' AND "mascot" = 'oilers'

Question: Which Year Left is the highest one that has a Location of east chicago, and a Year Joined of 1969, and a School of east chicago roosevelt?
SQL: SELECT MAX("year_left") FROM lake_ath_conf WHERE "location" = 'east chicago' AND "year_joined" = 1969 AND "school" = 'east chicago roosevelt'

Question: Which Year Left is the lowest one that has a School of calumet, and a Year Joined larger than 1993?
SQL: SELECT MIN("year_left") FROM lake_ath_conf WHERE "school" = 'calumet' AND "year_joined" > 1993