CREATE TABLE table_17713 ("Name of System" TEXT, "Location" TEXT, "Traction Type" TEXT, "Date  ( From ) " TEXT, "Date  ( To ) " TEXT, "Notes" TEXT)

how many times is the date (to) 1919?
SELECT COUNT("Notes") FROM table_17713 WHERE "Date (To)" = '1919'
SELECT COUNT("Notes") FROM "table_17713" WHERE "Date (To)" = '1919'