condition mean min max ZT0-3 1.7628949999999999 1.7628949999999999 1.7628949999999999 ZT4-7 2.47027 2.47027 2.47027 ZT8-11 3.8937049999999997 3.8937049999999997 3.8937049999999997 ZT12-15 3.17276 3.17276 3.17276 ZT16-19 2.776285 2.776285 2.776285 ZT20-23 1.643745 1.643745 1.643745