CREATE TABLE table_name_22 (area_2006_km² INTEGER, city VARCHAR(255), area_1996_km² VARCHAR(255))
Which area 2006 km² has a city of sopot, and an area 1996 km² smaller than 17.31?
    
SQL: SELECT MAX(area_2006_km²) FROM table_name_22 WHERE city = "sopot" AND area_1996_km² < 17.31