condition mean min max ZT0-3 21.326217 21.326217 21.326217 ZT4-7 33.2019045 33.2019045 33.2019045 ZT8-11 39.173965 39.173965 39.173965 ZT12-15 29.401488 29.401488 29.401488 ZT16-19 27.2135515 27.2135515 27.2135515 ZT20-23 22.365096 22.365096 22.365096