condition mean min max ZT0-3 4.3794575 3.78463 4.974285 ZT4-7 8.532995 8.532995 8.532995 ZT8-11 17.67305 17.67305 17.67305 ZT12-15 0 0 0 ZT16-19 15.131699999999999 15.131699999999999 15.131699999999999 ZT20-23 9.71128 9.71128 9.71128