condition mean min max ZT0-3 4.3215699999999995 4.3215699999999995 4.3215699999999995 ZT4-7 3.78543 3.78543 3.78543 ZT8-11 3.278295 3.278295 3.278295 ZT12-15 3.339765 3.339765 3.339765 ZT16-19 3.0099233333333335 3.0099233333333335 3.0099233333333335 ZT20-23 3.90981 3.90981 3.90981