Question: What is the average opened year of the line with 59 stations served and more than 145000000 journeys made per annum?
SQL: SELECT AVG("Opened") FROM "2-172174-1" WHERE "Stations served" = 59.0 AND "Journeys made (per annum)" > 145000000.0;

Question: What is the average opened year of line e, which had their last extension before 2003?
SQL: SELECT AVG("Opened") FROM "2-172174-1" WHERE "Line name" = 'line e' AND "Last extension" < 2003.0;