condition mean min max ZT0-3 0.4673756666666667 0.35044200000000003 0.5776375 ZT4-7 0.9031505000000001 0.9031505000000001 0.9031505000000001 ZT8-11 12.01675 12.01675 12.01675 ZT12-15 9.8152875 6.523825 13.106750000000002 ZT16-19 2.5269 2.5269 2.5269 ZT20-23 0.7519985 0.7519985 0.7519985