condition mean min max ZT0-3 13.327969999999999 4.74606 17.8599 ZT4-7 5.903919999999999 5.903919999999999 5.903919999999999 ZT8-11 6.961805 6.961805 6.961805 ZT12-15 6.6096975 5.22161 7.997785 ZT16-19 10.63665 10.63665 10.63665 ZT20-23 21.75875 21.75875 21.75875