condition mean min max ZT0-3 3.89482 3.89482 3.89482 ZT4-7 7.090725 7.090725 7.090725 ZT8-11 1.28901 1.28901 1.28901 ZT12-15 8.203955 8.203955 8.203955 ZT16-19 4.12449 4.12449 4.12449 ZT20-23 4.0916999999999994 4.0916999999999994 4.0916999999999994