condition mean min max ZT0-3 23.28547597 17.98495021 28.58600173 ZT4-7 37.2838308275 32.85337744 41.714284215 ZT8-11 52.5534572725 47.300609565 57.80630498 ZT12-15 27.108092015 17.034236135 37.181947895 ZT16-19 12.7660681425 11.841456404999999 13.690679880000001 ZT20-23 6.959359514249999 5.4261302945 8.492588733999998