CREATE TABLE table_60746 ("Year" FLOAT, "Competition" TEXT, "Venue" TEXT, "Position" TEXT, "Event" TEXT)

How many years had a 100 m hurdles event at the world championships in Osaka, Japan?
SELECT SUM("Year") FROM table_60746 WHERE "Event" = '100 m hurdles' AND "Competition" = 'world championships' AND "Venue" = 'osaka, japan'
SELECT SUM("Year") FROM "table_60746" WHERE "Competition" = 'world championships' AND "Event" = '100 m hurdles' AND "Venue" = 'osaka, japan'