condition mean min max ZT0-3 3.2829924999999998 3.048705 3.51728 ZT4-7 3.2011399999999997 3.2011399999999997 3.2011399999999997 ZT8-11 2.64752 2.64752 2.64752 ZT12-15 0 0 0 ZT16-19 3.0031 3.0031 3.0031 ZT20-23 3.27978 3.27978 3.27978