CREATE TABLE table_7868 ("Year" FLOAT, "Country" TEXT, "Champion" TEXT, "Total score" TEXT, "To Par [a ]" TEXT)

When the United States had a total score of 274 what was the average year?
SELECT AVG("Year") FROM table_7868 WHERE "Total score" = '274' AND "Country" = 'united states'
SELECT AVG("Year") FROM "table_7868" WHERE "Country" = 'united states' AND "Total score" = '274'