condition mean min max ZT0-3 7.4566575 6.197155 8.71616 ZT4-7 4.015215 4.015215 4.015215 ZT8-11 2.968495 2.968495 2.968495 ZT12-15 0 0 0 ZT16-19 4.05982 4.05982 4.05982 ZT20-23 4.777145 4.777145 4.777145