condition mean min max ZT0-3 24.437275 24.437275 24.437275 ZT4-7 25.0825935 25.0825935 25.0825935 ZT8-11 24.027775499999997 24.027775499999997 24.027775499999997 ZT12-15 24.8275335 24.8275335 24.8275335 ZT16-19 27.3995695 27.3995695 27.3995695 ZT20-23 42.314188 42.314188 42.314188