condition mean min max ZT0-3 0.6639463333333333 0.443154 1.003479 ZT4-7 0.5760985 0.5760985 0.5760985 ZT8-11 0.5999255 0.5999255 0.5999255 ZT12-15 1.8209149999999998 1.30908 2.33275 ZT16-19 1.653965 1.653965 1.653965 ZT20-23 1.57049 1.57049 1.57049