condition mean min max ZT0-3 2.9511649999999996 2.9511649999999996 2.9511649999999996 ZT4-7 4.31265 4.31265 4.31265 ZT8-11 1.521435 1.521435 1.521435 ZT12-15 2.189295 2.189295 2.189295 ZT16-19 4.430054999999999 4.430054999999999 4.430054999999999 ZT20-23 2.57902 2.57902 2.57902