condition mean min max ZT0-3 50.507733333333334 47.078 55.792699999999996 ZT4-7 48.2041 48.2041 48.2041 ZT8-11 48.763549999999995 48.763549999999995 48.763549999999995 ZT12-15 67.211825 65.65785 68.76580000000001 ZT16-19 63.746 63.746 63.746 ZT20-23 64.633 64.633 64.633