condition mean min max ZT0-3 0.6238966666666667 0.0 1.87169 ZT4-7 6.328239999999999 6.328239999999999 6.328239999999999 ZT8-11 3.787745 3.787745 3.787745 ZT12-15 5.8556 4.58 7.1312 ZT16-19 2.805165 2.805165 2.805165 ZT20-23 3.931165 3.931165 3.931165