CREATE TABLE table_42497 ("Year" FLOAT, "Winner" TEXT, "School" TEXT, "Position" TEXT, "Points" TEXT, "% of Points Possible" TEXT)

What is the year of the winner from the army school, plays the halfback position, and has a % of points possible of 39.01%?
SELECT SUM("Year") FROM table_42497 WHERE "School" = 'army' AND "Position" = 'halfback' AND "% of Points Possible" = '39.01%'
SELECT SUM("Year") FROM "table_42497" WHERE "% of Points Possible" = '39.01%' AND "Position" = 'halfback' AND "School" = 'army'