condition mean min max ZT0-3 7.44744 7.44744 7.44744 ZT4-7 6.6934000000000005 6.6934000000000005 6.6934000000000005 ZT8-11 5.11367 5.11367 5.11367 ZT12-15 6.80933 6.80933 6.80933 ZT16-19 8.491795 8.491795 8.491795 ZT20-23 6.505535 6.505535 6.505535