condition mean min max ZT0-3 19.966779 19.966779 19.966779 ZT4-7 23.0961075 23.0961075 23.0961075 ZT8-11 24.703164 24.703164 24.703164 ZT12-15 20.6969955 20.6969955 20.6969955 ZT16-19 39.689310500000005 39.689310500000005 39.689310500000005 ZT20-23 30.4748795 30.4748795 30.4748795