condition mean min max ZT0-3 5.869936666666667 2.8157550000000002 8.196885 ZT4-7 2.468115 2.468115 2.468115 ZT8-11 2.9270449999999997 2.9270449999999997 2.9270449999999997 ZT12-15 5.94402 5.77665 6.11139 ZT16-19 6.240795 6.240795 6.240795 ZT20-23 8.452075 8.452075 8.452075