condition mean min max ZT0-3 20.806075 20.76365 20.8485 ZT4-7 19.20295 19.20295 19.20295 ZT8-11 17.30405 17.30405 17.30405 ZT12-15 0 0 0 ZT16-19 22.11395 22.11395 22.11395 ZT20-23 23.97685 23.97685 23.97685