condition mean min max ZT0-3 184.349432365 89.47235472999999 279.22651 ZT4-7 56.48985242 49.74748348 63.23222136 ZT8-11 65.76599186249999 57.961888675 73.57009504999999 ZT12-15 54.2275326875 42.89021976 65.564845615 ZT16-19 38.95889151749999 34.364271415 43.553511619999995 ZT20-23 26.161006262500003 22.067227985000002 30.254784540000003