condition mean min max ZT0-3 30.232 28.7156 31.748399999999997 ZT4-7 20.0721 20.0721 20.0721 ZT8-11 18.82 18.82 18.82 ZT12-15 0 0 0 ZT16-19 20.6337 20.6337 20.6337 ZT20-23 23.0203 23.0203 23.0203