condition mean min max ZT0-3 4.399255 4.399255 4.399255 ZT4-7 3.26997 3.26997 3.26997 ZT8-11 4.26826 4.26826 4.26826 ZT12-15 4.767435 4.767435 4.767435 ZT16-19 5.903309999999999 5.903309999999999 5.903309999999999 ZT20-23 4.600215 4.600215 4.600215