CREATE TABLE table_28564 ("Finished" TEXT, "Performance Order" FLOAT, "Percentage of votes" TEXT, "Artist" TEXT, "Act" TEXT, "Semi Finals Result" TEXT)

Name the number of semi final results for 12 performance order
SELECT COUNT("Semi Finals Result") FROM table_28564 WHERE "Performance Order" = '12'
SELECT COUNT("Semi Finals Result") FROM "table_28564" WHERE "Performance Order" = '12'