condition mean min max ZT0-3 4.438256666666667 2.7174199999999997 5.92507 ZT4-7 3.0163450000000003 3.0163450000000003 3.0163450000000003 ZT8-11 2.585715 2.585715 2.585715 ZT12-15 4.3128925 4.08489 4.540895 ZT16-19 3.966025 3.966025 3.966025 ZT20-23 6.7103649999999995 6.7103649999999995 6.7103649999999995