condition mean min max ZT0-3 1.5365533333333332 1.5365533333333332 1.5365533333333332 ZT4-7 0.884691 0.884691 0.884691 ZT8-11 0.6740459999999999 0.6740459999999999 0.6740459999999999 ZT12-15 1.51418 1.51418 1.51418 ZT16-19 0.954821 0.954821 0.954821 ZT20-23 1.081696 1.081696 1.081696