condition mean min max ZT0-3 18.20035 18.20035 18.20035 ZT4-7 19.414 19.414 19.414 ZT8-11 8.883915 8.883915 8.883915 ZT12-15 11.80915 11.80915 11.80915 ZT16-19 15.1874 15.1874 15.1874 ZT20-23 18.1415 18.1415 18.1415