condition mean min max ZT0-3 969.578519 969.578519 969.578519 ZT4-7 858.473119 858.473119 858.473119 ZT8-11 619.0502515000001 619.0502515000001 619.0502515000001 ZT12-15 502.8804715 502.8804715 502.8804715 ZT16-19 235.456082 235.456082 235.456082 ZT20-23 91.4795595 91.4795595 91.4795595