condition mean min max ZT0-3 2.4431775 2.2893299999999996 2.5970250000000004 ZT4-7 2.271535 2.271535 2.271535 ZT8-11 1.55664 1.55664 1.55664 ZT12-15 0 0 0 ZT16-19 2.685155 2.685155 2.685155 ZT20-23 2.57806 2.57806 2.57806