CREATE TABLE airports (apid DECIMAL, name TEXT, city TEXT, country TEXT, x DECIMAL, y DECIMAL, elevation DECIMAL, iata TEXT, icao TEXT)
CREATE TABLE airlines (alid DECIMAL, name TEXT, iata TEXT, icao TEXT, callsign TEXT, country TEXT, active TEXT)
CREATE TABLE routes (rid DECIMAL, dst_apid DECIMAL, dst_ap TEXT, src_apid DECIMAL, src_ap TEXT, alid DECIMAL, airline TEXT, codeshare TEXT)

Which countries has the most number of airlines whose active status is 'Y'?
SELECT country FROM airlines WHERE active = 'Y' GROUP BY country ORDER BY COUNT(*) DESC LIMIT 1
SELECT "country" FROM "airlines" WHERE "active" = 'Y' GROUP BY "country" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1