condition mean min max ZT0-3 20.76425 20.0552 21.473300000000002 ZT4-7 19.6783 19.6783 19.6783 ZT8-11 28.2137 28.2137 28.2137 ZT12-15 0 0 0 ZT16-19 35.14575 35.14575 35.14575 ZT20-23 32.0645 32.0645 32.0645