condition mean min max ZT0-3 18.270975 14.4454 22.09655 ZT4-7 8.825385 8.825385 8.825385 ZT8-11 7.0614099999999995 7.0614099999999995 7.0614099999999995 ZT12-15 0 0 0 ZT16-19 14.08795 14.08795 14.08795 ZT20-23 16.245649999999998 16.245649999999998 16.245649999999998