condition mean min max ZT0-3 4.5638775 4.46666 4.6610949999999995 ZT4-7 5.56222 5.56222 5.56222 ZT8-11 4.475095 4.475095 4.475095 ZT12-15 0 0 0 ZT16-19 6.88242 6.88242 6.88242 ZT20-23 7.576115 7.576115 7.576115