condition mean min max ZT0-3 20.7746 20.14245 21.406750000000002 ZT4-7 22.68325 22.68325 22.68325 ZT8-11 27.3096 27.3096 27.3096 ZT12-15 0 0 0 ZT16-19 37.063500000000005 37.063500000000005 37.063500000000005 ZT20-23 28.60415 28.60415 28.60415