condition mean min max ZT0-3 16.428975 15.2135 17.64445 ZT4-7 13.571349999999999 13.571349999999999 13.571349999999999 ZT8-11 28.6804 28.6804 28.6804 ZT12-15 0 0 0 ZT16-19 33.211600000000004 33.211600000000004 33.211600000000004 ZT20-23 25.21 25.21 25.21