condition mean min max ZT0-3 7.620193 7.620193 7.620193 ZT4-7 10.4261315 10.4261315 10.4261315 ZT8-11 9.500691 9.500691 9.500691 ZT12-15 8.567556 8.567556 8.567556 ZT16-19 8.470574 8.470574 8.470574 ZT20-23 8.0473365 8.0473365 8.0473365