condition mean min max ZT0-3 2.2433883333333333 1.62952 2.6827699999999997 ZT4-7 1.242765 1.242765 1.242765 ZT8-11 0.641693 0.641693 0.641693 ZT12-15 2.5967825 2.54319 2.6503750000000004 ZT16-19 2.605165 2.605165 2.605165 ZT20-23 4.47024 4.47024 4.47024