condition mean min max ZT0-3 54.178318 54.178318 54.178318 ZT4-7 31.6924135 31.6924135 31.6924135 ZT8-11 21.4549765 21.4549765 21.4549765 ZT12-15 30.641852999999998 30.641852999999998 30.641852999999998 ZT16-19 24.551856 24.551856 24.551856 ZT20-23 23.9551465 23.9551465 23.9551465