condition mean min max ZT0-3 2.9756349999999996 2.12973 3.8215399999999997 ZT4-7 3.57238 3.57238 3.57238 ZT8-11 3.837325 3.837325 3.837325 ZT12-15 0 0 0 ZT16-19 3.0912800000000002 3.0912800000000002 3.0912800000000002 ZT20-23 2.74005 2.74005 2.74005