condition mean min max ZT0-3 2.347995 2.347995 2.347995 ZT4-7 0.421863 0.421863 0.421863 ZT8-11 0.461335 0.461335 0.461335 ZT12-15 0.83705 0.83705 0.83705 ZT16-19 0.738077 0.738077 0.738077 ZT20-23 2.75268 2.75268 2.75268