condition mean min max ZT0-3 23.63485 23.63485 23.63485 ZT4-7 16.26315 16.26315 16.26315 ZT8-11 11.23865 11.23865 11.23865 ZT12-15 14.6548 14.6548 14.6548 ZT16-19 25.5734 25.5734 25.5734 ZT20-23 29.0047 29.0047 29.0047