CREATE TABLE table_name_26 (year INT, competition VARCHAR, notes VARCHAR)

Which Year has a Competition of european championships, and Notes of 66.81 m?
SELECT SUM(year) FROM table_name_26 WHERE competition = "european championships" AND notes = "66.81 m"
SELECT SUM("year") FROM "table_name_26" WHERE "66.81 m" = "notes" AND "competition" = "european championships"