condition mean min max ZT0-3 21.9204491325 18.20025476 25.640643505 ZT4-7 27.32919466 25.309605835 29.348783485 ZT8-11 33.804828064999995 30.694318799999998 36.91533733 ZT12-15 39.10384891 38.590693290000004 39.61700453 ZT16-19 39.0046992375 37.04995776 40.959440715 ZT20-23 44.3130082375 41.389840809999995 47.236175665000005