condition mean min max ZT0-3 14.7423 14.7423 14.7423 ZT4-7 4.88759 4.88759 4.88759 ZT8-11 4.45383 4.45383 4.45383 ZT12-15 9.70923 9.70923 9.70923 ZT16-19 21.0979 21.0979 21.0979 ZT20-23 23.32665 23.32665 23.32665