condition mean min max ZT0-3 21.012966666666664 12.1214 26.364649999999997 ZT4-7 7.083394999999999 7.083394999999999 7.083394999999999 ZT8-11 10.452325 10.452325 10.452325 ZT12-15 18.507624999999997 16.10675 20.908499999999997 ZT16-19 24.37695 24.37695 24.37695 ZT20-23 31.4801 31.4801 31.4801