condition mean min max ZT0-3 19.3684 19.3684 19.3684 ZT4-7 18.85735 18.85735 18.85735 ZT8-11 19.2462 19.2462 19.2462 ZT12-15 18.74315 18.74315 18.74315 ZT16-19 41.4364 41.4364 41.4364 ZT20-23 23.83145 23.83145 23.83145