condition mean min max ZT0-3 2.359008333333333 2.17631 2.45681 ZT4-7 2.64948 2.64948 2.64948 ZT8-11 2.18264 2.18264 2.18264 ZT12-15 1.6206025 1.5122900000000001 1.728915 ZT16-19 1.768855 1.768855 1.768855 ZT20-23 2.520125 2.520125 2.520125