condition mean min max ZT0-3 8.728805 7.3903 10.067309999999999 ZT4-7 5.7251449999999995 5.7251449999999995 5.7251449999999995 ZT8-11 4.63953 4.63953 4.63953 ZT12-15 0 0 0 ZT16-19 7.37763 7.37763 7.37763 ZT20-23 7.634405 7.634405 7.634405