CREATE TABLE table_204_131 (id DECIMAL, "tops design code" TEXT, "electrical system" TEXT, "max speed" TEXT, "weight" TEXT, "brakes" TEXT, "route availability" DECIMAL, "notes" TEXT)

what is the top speed of the class 08
SELECT "max speed" FROM table_204_131 ORDER BY "max speed" DESC LIMIT 1
SELECT "max speed" FROM "table_204_131" ORDER BY "max speed" DESC NULLS LAST LIMIT 1