condition mean min max ZT0-3 20.5259 20.5259 20.5259 ZT4-7 20.756500000000003 20.756500000000003 20.756500000000003 ZT8-11 17.389850000000003 17.389850000000003 17.389850000000003 ZT12-15 25.51015 25.51015 25.51015 ZT16-19 21.915100000000002 21.915100000000002 21.915100000000002 ZT20-23 23.025599999999997 23.025599999999997 23.025599999999997