condition mean min max ZT0-3 11.787469999999999 6.64891 15.43175 ZT4-7 5.977069999999999 5.977069999999999 5.977069999999999 ZT8-11 6.58443 6.58443 6.58443 ZT12-15 8.9304275 7.682455 10.1784 ZT16-19 9.29769 9.29769 9.29769 ZT20-23 12.3265 12.3265 12.3265