condition mean min max ZT0-3 244.359909 244.359909 244.359909 ZT4-7 267.473754 267.473754 267.473754 ZT8-11 291.66484349999996 291.66484349999996 291.66484349999996 ZT12-15 212.2217765 212.2217765 212.2217765 ZT16-19 321.1797075 321.1797075 321.1797075 ZT20-23 288.5719605 288.5719605 288.5719605