condition mean min max ZT0-3 2.17853 1.955555 2.52796 ZT4-7 1.377615 1.377615 1.377615 ZT8-11 1.056452 1.056452 1.056452 ZT12-15 1.431605 1.3492000000000002 1.5140099999999999 ZT16-19 1.20567 1.20567 1.20567 ZT20-23 2.0142499999999997 2.0142499999999997 2.0142499999999997