condition mean min max ZT0-3 2.35398 2.1312349999999998 2.5767249999999997 ZT4-7 5.44225 5.44225 5.44225 ZT8-11 4.1507950000000005 4.1507950000000005 4.1507950000000005 ZT12-15 0 0 0 ZT16-19 2.66635 2.66635 2.66635 ZT20-23 2.813765 2.813765 2.813765