condition mean min max ZT0-3 4.949999999999999 4.949999999999999 4.949999999999999 ZT4-7 1.6 1.6 1.6 ZT8-11 9.25 9.25 9.25 ZT12-15 8.35 8.35 8.35 ZT16-19 20.25 20.25 20.25 ZT20-23 9.899999999999999 9.899999999999999 9.899999999999999