condition mean min max ZT0-3 34.667649 34.667649 34.667649 ZT4-7 30.4539715 30.4539715 30.4539715 ZT8-11 26.119383499999998 26.119383499999998 26.119383499999998 ZT12-15 33.8595575 33.8595575 33.8595575 ZT16-19 22.033032 22.033032 22.033032 ZT20-23 38.688916 38.688916 38.688916