Table: airport_traffic_4
Columns: year
lansing_lan
detroit_dtw
grand_rapids_grr
flint_fnt
kalamazoo_azo
saginaw_mbs

Question: What was the passenger fare for Lansing, when the passenger fare for Kalamazoo was $599.39?
SQL: SELECT "lansing_lan" FROM airport_traffic_4 WHERE "kalamazoo_azo" = '$599.39'

Question: For how many years did Detroit have a passenger fare of $307.29?
SQL: SELECT SUM("year") FROM airport_traffic_4 WHERE "detroit_dtw" = '$307.29'

Question: What was the passenger fare for Grand Rapids, when the passenger fare for Detroit was $378.55?
SQL: SELECT "grand_rapids_grr" FROM airport_traffic_4 WHERE "detroit_dtw" = '$378.55'

Question: Before the year 2010, and when Kalamazoo had a passenger fare of $517.32, what was the passenger fare for Detroit?
SQL: SELECT "detroit_dtw" FROM airport_traffic_4 WHERE "year" < 2010 AND "kalamazoo_azo" = '$517.32'