condition mean min max ZT0-3 3.964155 3.964155 3.964155 ZT4-7 4.05633 4.05633 4.05633 ZT8-11 2.73399 2.73399 2.73399 ZT12-15 3.86923 3.86923 3.86923 ZT16-19 3.8727 3.8727 3.8727 ZT20-23 3.4789399999999997 3.4789399999999997 3.4789399999999997