condition mean min max ZT0-3 138.329687 138.329687 138.329687 ZT4-7 137.17571249999997 137.17571249999997 137.17571249999997 ZT8-11 170.170415 170.170415 170.170415 ZT12-15 164.6819685 164.6819685 164.6819685 ZT16-19 188.633792 188.633792 188.633792 ZT20-23 170.6038205 170.6038205 170.6038205