condition mean min max ZT0-3 13.909963333333334 7.7537400000000005 17.77525 ZT4-7 7.6927900000000005 7.6927900000000005 7.6927900000000005 ZT8-11 7.01009 7.01009 7.01009 ZT12-15 8.4461875 8.091675 8.800699999999999 ZT16-19 9.96069 9.96069 9.96069 ZT20-23 18.3765 18.3765 18.3765