condition mean min max ZT0-3 22.047775 21.1477 22.94785 ZT4-7 20.076050000000002 20.076050000000002 20.076050000000002 ZT8-11 21.298 21.298 21.298 ZT12-15 0 0 0 ZT16-19 27.38035 27.38035 27.38035 ZT20-23 36.82215 36.82215 36.82215