condition mean min max ZT0-3 6.5086525 6.238935 6.77837 ZT4-7 4.77791 4.77791 4.77791 ZT8-11 4.000825000000001 4.000825000000001 4.000825000000001 ZT12-15 0 0 0 ZT16-19 8.86833 8.86833 8.86833 ZT20-23 8.08522 8.08522 8.08522