condition mean min max ZT0-3 7.949999999999999 7.949999999999999 7.949999999999999 ZT4-7 12.7 12.7 12.7 ZT8-11 19.35 19.35 19.35 ZT12-15 32.95 32.95 32.95 ZT16-19 42.55 42.55 42.55 ZT20-23 23.25 23.25 23.25