condition mean min max ZT0-3 3.7385 3.7385 3.7385 ZT4-7 2.289415 2.289415 2.289415 ZT8-11 5.6308050000000005 5.6308050000000005 5.6308050000000005 ZT12-15 7.931620000000001 7.931620000000001 7.931620000000001 ZT16-19 7.875795 7.875795 7.875795 ZT20-23 4.758675 4.758675 4.758675