condition mean min max ZT0-3 3.1707599999999996 3.1707599999999996 3.1707599999999996 ZT4-7 1.717635 1.717635 1.717635 ZT8-11 2.657565 2.657565 2.657565 ZT12-15 3.340775 3.340775 3.340775 ZT16-19 4.42286 4.42286 4.42286 ZT20-23 2.9966049999999997 2.9966049999999997 2.9966049999999997