Question: What is the total number of stations with a line that is U 6?
SQL: SELECT SUM("Stations") FROM "2-1167316-2" WHERE "Line" = 'U 6';

Question: Which route has 21 stations?
SQL: SELECT "Route" FROM "2-1167316-2" WHERE "Stations" = 21.0;

Question: Which line was green?
SQL: SELECT "Line" FROM "2-1167316-2" WHERE "Colour" = 'green';