condition mean min max ZT0-3 1.6576791666666666 1.0656275 2.322885 ZT4-7 1.80627 1.80627 1.80627 ZT8-11 0.627915 0.627915 0.627915 ZT12-15 1.4968488500500001 1.29837 1.6953277001 ZT16-19 0.8019765000000001 0.8019765000000001 0.8019765000000001 ZT20-23 2.11763 2.11763 2.11763