condition mean min max ZT0-3 13.306496 13.306496 13.306496 ZT4-7 17.933861 17.933861 17.933861 ZT8-11 19.182794 19.182794 19.182794 ZT12-15 16.9160355 16.9160355 16.9160355 ZT16-19 17.302004 17.302004 17.302004 ZT20-23 18.8042825 18.8042825 18.8042825