condition mean min max ZT0-3 1.9604216666666667 1.10495 2.601715 ZT4-7 0.8322635 0.8322635 0.8322635 ZT8-11 3.00392 3.00392 3.00392 ZT12-15 5.556135 4.912255 6.2000150000000005 ZT16-19 4.17016 4.17016 4.17016 ZT20-23 4.532185 4.532185 4.532185