condition mean min max ZT0-3 4.884655 4.470655 5.298655 ZT4-7 2.542195 2.542195 2.542195 ZT8-11 3.5979599999999996 3.5979599999999996 3.5979599999999996 ZT12-15 0 0 0 ZT16-19 9.97476 9.97476 9.97476 ZT20-23 8.595875 8.595875 8.595875