condition mean min max ZT0-3 7.4943525 4.753705 10.235 ZT4-7 11.082335 11.082335 11.082335 ZT8-11 7.347715 7.347715 7.347715 ZT12-15 0 0 0 ZT16-19 6.79854 6.79854 6.79854 ZT20-23 16.6493 16.6493 16.6493