condition mean min max ZT0-3 18.084803 18.084803 18.084803 ZT4-7 13.287821999999998 13.287821999999998 13.287821999999998 ZT8-11 12.36994 12.36994 12.36994 ZT12-15 15.1887255 15.1887255 15.1887255 ZT16-19 18.177058000000002 18.177058000000002 18.177058000000002 ZT20-23 18.840343 18.840343 18.840343