condition mean min max ZT0-3 1.414815 1.414815 1.414815 ZT4-7 0.9258994999999999 0.9258994999999999 0.9258994999999999 ZT8-11 1.0338465 1.0338465 1.0338465 ZT12-15 1.5714700000000001 1.5714700000000001 1.5714700000000001 ZT16-19 2.249455 2.249455 2.249455 ZT20-23 1.6532749999999998 1.6532749999999998 1.6532749999999998