condition mean min max ZT0-3 2.4107149999999997 2.4107149999999997 2.4107149999999997 ZT4-7 1.81131 1.81131 1.81131 ZT8-11 2.0580049999999996 2.0580049999999996 2.0580049999999996 ZT12-15 3.0125349999999997 3.0125349999999997 3.0125349999999997 ZT16-19 2.3210499999999996 2.3210499999999996 2.3210499999999996 ZT20-23 1.97247 1.97247 1.97247