condition mean min max ZT0-3 17.703461666666666 9.207485 22.63995 ZT4-7 9.46626 9.46626 9.46626 ZT8-11 11.366589999999999 11.366589999999999 11.366589999999999 ZT12-15 14.524799999999999 11.645399999999999 17.4042 ZT16-19 19.707349999999998 19.707349999999998 19.707349999999998 ZT20-23 21.26395 21.26395 21.26395