condition mean min max ZT0-3 26.966016666666665 23.58865 32.367 ZT4-7 22.3901 22.3901 22.3901 ZT8-11 20.2058 20.2058 20.2058 ZT12-15 30.7757 24.22135 37.33005 ZT16-19 21.551099999999998 21.551099999999998 21.551099999999998 ZT20-23 26.6706 26.6706 26.6706