condition mean min max ZT0-3 4.914255 4.914255 4.914255 ZT4-7 4.023905 4.023905 4.023905 ZT8-11 3.065035 3.065035 3.065035 ZT12-15 2.97368 2.97368 2.97368 ZT16-19 5.55625 5.55625 5.55625 ZT20-23 4.89071 4.89071 4.89071