condition mean min max ZT0-3 2.6724733333333335 1.556015 3.861325 ZT4-7 2.9471 2.9471 2.9471 ZT8-11 9.440425000000001 9.440425000000001 9.440425000000001 ZT12-15 11.0184125 9.735525 12.3013 ZT16-19 6.697035 6.697035 6.697035 ZT20-23 6.12735 6.12735 6.12735