condition mean min max ZT0-3 6.248925 5.5405750000000005 6.843845 ZT4-7 4.21558 4.21558 4.21558 ZT8-11 4.61985 4.61985 4.61985 ZT12-15 7.075457500000001 6.862205 7.28871 ZT16-19 6.543085 6.543085 6.543085 ZT20-23 6.875845 6.875845 6.875845