CREATE TABLE table_80261 ("Year" FLOAT, "Tournament" TEXT, "Venue" TEXT, "Result" TEXT, "Event" TEXT)

What is earliest year that had a 50km event with a 2nd place result played in London, United Kingdom?
SELECT MIN("Year") FROM table_80261 WHERE "Event" = '50km' AND "Result" = '2nd' AND "Venue" = 'london, united kingdom'
SELECT MIN("Year") FROM "table_80261" WHERE "Event" = '50km' AND "Result" = '2nd' AND "Venue" = 'london, united kingdom'