condition mean min max ZT0-3 23.428516666666667 21.368299999999998 24.8902 ZT4-7 24.399749999999997 24.399749999999997 24.399749999999997 ZT8-11 32.61475 32.61475 32.61475 ZT12-15 45.70985 43.69725 47.72245 ZT16-19 31.11835 31.11835 31.11835 ZT20-23 28.88635 28.88635 28.88635