condition mean min max ZT0-3 12.14085 11.61745 12.66425 ZT4-7 14.8264 14.8264 14.8264 ZT8-11 17.65905 17.65905 17.65905 ZT12-15 0 0 0 ZT16-19 19.400599999999997 19.400599999999997 19.400599999999997 ZT20-23 15.18 15.18 15.18