condition mean min max ZT0-3 29.5977976 23.79499974 35.40059546 ZT4-7 13.93146819 12.811162405 15.051773975 ZT8-11 14.3314673825 11.478936545 17.18399822 ZT12-15 13.9424219475 12.866359880000001 15.018484014999999 ZT16-19 13.095019407499999 11.661017704999999 14.529021109999999 ZT20-23 14.722606155 13.677609454999999 15.767602855