condition mean min max ZT0-3 2.16275 2.16275 2.16275 ZT4-7 1.26715 1.26715 1.26715 ZT8-11 2.05329 2.05329 2.05329 ZT12-15 6.243399999999999 6.243399999999999 6.243399999999999 ZT16-19 5.511345 5.511345 5.511345 ZT20-23 1.647605 1.647605 1.647605