condition mean min max ZT0-3 26.874375 24.8057 28.94305 ZT4-7 17.459600000000002 17.459600000000002 17.459600000000002 ZT8-11 7.55974 7.55974 7.55974 ZT12-15 0 0 0 ZT16-19 11.13335 11.13335 11.13335 ZT20-23 20.20485 20.20485 20.20485