condition mean min max ZT0-3 4.954063333333333 3.9772 6.714695000000001 ZT4-7 7.8386700000000005 7.8386700000000005 7.8386700000000005 ZT8-11 8.014420000000001 8.014420000000001 8.014420000000001 ZT12-15 20.1229 17.75655 22.48925 ZT16-19 15.27515 15.27515 15.27515 ZT20-23 10.375715 10.375715 10.375715