condition mean min max ZT0-3 24.44385 21.4514 29.4523 ZT4-7 20.5843 20.5843 20.5843 ZT8-11 21.124049999999997 21.124049999999997 21.124049999999997 ZT12-15 17.140375 14.123650000000001 20.1571 ZT16-19 15.605899999999998 15.605899999999998 15.605899999999998 ZT20-23 24.189 24.189 24.189